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NVIDIA nForce 790i SLI Ultra and GeForce 9800 GX2
Date: Mar 18, 2008
Author: Marco Chiappetta
Introducing the nForce 790i SLI Ultra

Way back in late 2006, NVIDIA simultaneously unveiled a new flagship GPU and desktop chipset that became the foundation of what NVIDIA was calling the "ultimate gaming platform".  At the time, the combination of a pair of GeForce 8800 GTX graphics cards and an nForce 680i SLI-based motherboard was clearly the most powerful hardware combo available for gamers.  And here we are, nearly a year and a half later in early 2008, and still that combo is tough to beat; truly a testament to NVIDIA's engineering abilities and execution.

Since the introduction of that version of NVIDIA's ultimate gaming platform, the company's product stack has changed quite a bit.  New GPUs have hit the scene in all segments of the market and desktop chipsets for both Intel and AMD platforms have been released as well.  But NVIDIA never went all out and released a full-on update to their proposed ultimate gaming platform, complete with a new flagship graphics card and nForce chipset - until today that is.

Rumors abound for the last few months regarding the GeForce 9800 GX2 and nForce 790i SLI Ultra, and today we can finally show you what all the fuss has been about.  This is a big day for NVIDIA.  A new desktop chipset complete with a DDR3-based memory controller is here, along with a dual-GPU powered monolith of a graphics card that is NVIDIA's most powerful to date.  Together, the combination of a GeForce 9800 GX2 (or GX2s), with the nForce 790i SLI Ultra chipset, redefine the high-end of desktop PC gaming hardware.  Read on for the details and to see just what 2008's version of the ultimate gaming platform can do...

Quad-SLI is Coming: The nForce 790i SLI Ultra with a pair of GeForce 9800 GX2 cards

NVIDIA nForce 790i SLI Ultra
Specifications and Features

First, let's talk a bit about the nForce 790i SLI Ultra.  Although the main focus of this article will revolve around this chipset, NVIDIA is actually releasing a few others as well.  The nForce 790i SLI and 750i SLI will also be debuting soon, with similar capabilities and feature sets.  As has historically been the case with NVIDIA's desktop chipsets, as you move further down the product stack, prices go down, and a few high-end features are stripped away.  In this case, the 750i SLI is a DDR2-based chipset, capable of 2-way SLI, with a single Gigabit Ethernet connector and PCI Express 2.0 support by way of the NF200 chip.

The nForce 790i SLI and 790i SLI Ultra, however, are more difficult to differentiate.  Essentially, the two chipsets are identical.  The Ultra version of the chipset is more vigorously binned and is capable of DDR3 memory speeds in excess of 2GHz.  The non-Ultra 790i SLI is officially supports DDR3 memory speeds as high as 1333MHz.  Other notable features to the 790i SLI chipset include 60 lanes of PCI Express connectivity with native gen 2 support, with 10 USB ports, ESA, Media Shield, and First Packet support, in addition to three-way and Quad-SLI support.

790i and 750i SLI High Level Overviews

Below we have a high-level overview of the nForce 790i SLI Ultra chipset's high level architecture and main features.  As the illustration shows, the 790i SLI Ultra (and non-Ultra version of the chipset) is a two chip solution consisting of the nForce 790i Ultra SLI SPP in the traditional Northbridge position and the 790i SLI Ultra MCP in the Southbridge position.

NVIDIA nForce 790i SLI Ultra Chipset Diagram

The chipset has full support for all Intel desktop processors with front side bus speeds as high as 1600MHz.  The DDR3 memory controller in the SPP is compatible with EPP 2.0 and officially capable of speeds up to 2000MHz, although higher speeds are possible with overclocking.  32 of the chipset's PCI Express lanes reside in the SPP, with the remainder coming by way of the MCP.  And the two chips are linked via HyperTransport.  We should note that the SPP's lanes are gen 2, while the rest are gen 1.  What NVIDIA has done here is essentially bring the NF200 chip present on the 780i SLI and 750i SLI chipsets and brought it right onto the SPP.

Although the nForce 790i Ultra SLI MCP has a new name here in the block diagram, it is still the NF570 chip used on motherboards dating back to the introduction of the nForce 500 series.  It would be nice if NVIDIA revamped this chip and produced it on a more advanced process node to bring power consumption down, but from a feature standpoint it's still as robust as any other solution currently on the market.

NVIDIA nForce 750i SLI Chipset Diagram

The nForce 750i SLI's feature set is similar to its high-end counterpart in some respects.  Both chipsets support all current Intel processors and both are linked via HyperTransport.  The nForce 750i SLI, however, utilizes a third chip - the NF200 - for its PCI Express 2.0 connectivity and the chipset has fewer PCI Express lanes overall.  The nForce 750i SLI's MCP is also pared down a bit with fewer USB and SATA ports, and only a single Gigabit Ethernet controller.

Feature Spotlight: ESA

As it stands today, many of the major components in a typical enthusiast class PC have built-in mechanisms for monitoring the health of the device.  Processors and GPUs have internal thermal diodes for monitoring temperatures, and graphics cards and motherboards have sensors for monitoring a myriad of voltages, temperatures, and things like fan speeds.  Other components, however, like cases, power supplies, and cooling systems, for example, usually don’t have any such mechanism.  And even if they do, odds are it uses a proprietary interface that isn’t universally compatible.

To remedy this situation, the crew at NVIDIA architected a new open standard that has been gaining traction across the industry.  ESA, or the Enthusiast System Architecture, as it is known, was designed for real-time monitoring and control of PC power supplies, chassis and water cooling systems.

The ESA standard is built around the USB HID (Human Interface Device) specification and has recently been approved by the USB-if HID subcommittee.  ESA is essentially a hardware and software based interface that takes data collected by analog sensors and converts it to digital information that can accessed via software.  Below are a handful of slides that explain some of the inner workings of ESA.

ESA - Enthusiast System Architecture
Knowledge is Power


If you take a look at the slides above, they'll give you an idea as to what NVIDIA is doing with ESA.  As you'll see, ESA compliant hardware features an embedded microcontroller and will connect to a system via a standard USB cable.  Currently, NVIDIA has developed new software as an extension of their nTune system utility for use with ESA, but partners that build ESA compliant hardware can also incorporate the data into their own proprietary PC health monitoring / status applications, like Gigabyte's Easy Tune or Asus' PC Probe, for example.


The question remains, how would ESA compliant hardware affect you as an enthusiast?  As an example, let's consider a case.  An ESA compliant case could have a number of thermal sensors throughout its interior with their positions throughout the enclosure recorded in ROM.  The fans used in the case are also connected to an ESA compliant controller.  Should one of the thermal sensors in the case read a high temperature, the ESA microcontroller can instruct the necessary case fans to spin up, which will reduce the temperature.  Cooling devices can also gain new functionality like real-time monitoring of water temperatures and flow-rates and controlled fans and pumps.  And the data collected can be viewed through software or even by glancing down at LEDs that can be programmed to change colors in different scenarios.



When ESA was first announced, NVIDIA named a number of high-profile partners the company claimed were backing the ESA standard, like Asus, Dell, CoolIT, Cooler Master, Gigabyte, MSI, Thermaltake, among others.  Since that initial announcement, we've seen a number of products at events like CES that were ESA compliant.  And for this launch, NVIDIA showed off another group of products that take advantage of ESA.  We've got Silverstone's TJ10 ESA eidtion case pictured above, as well as Thermaltake's Big Water 780e liquid-cooling system, and a Top Power PSU too.  Although it wasn't clear that ESA would take off when the standard was unveiled, it appears now that more and more manufacturers are jumping on board.

EPP 2.0, Broadcast and PW Short

Like the nForce 680i and 780i SLI that came before it, the new nForce 790i SLI Ultra has support for Enhanced Performance Profiles, or EPP.  EPP is a feature designed to maximize system performance by automatically tweaking memory and CPU frequencies, multipliers and voltages. The different with the nForce 790i SLI Ultra though, is that EPP - now up to revision 2.0 - supports DDR3 memory.

EPP 2.0 - Enhanced Performance Profiles
EPP for DDR3

The nForce 790i SLU Ultra's DDR3 Memory Interface

Like EPP, EPP 2.0 is an open memory standard that has been adopted by a number of motherboard and memory manufacturers. Enhanced Performance Profiles 2.0 increases performance by taking advantage of additional memory parameters added to the unused portion of a standard JEDEC Serial Presence Detect, or SPD.  The JEDEC specification only calls for small amount of data to be stored in a standard SPD, which leaves a significant amount of unused space.  EPP 2.0 takes advantage of this space to store specific information about the modules, like their maximum supported frequencies and timings.

EPP 2.0 also needs motherboard support to function.  To support EPP 2.0 a motherboard's BIOS has to be programmed to snoop the upper portion of the SPD to find the relevant configuration data.  That data is then used in conjunction with a pre-determined set of parameters stored in the system BIOS to automatically tweak performance.

For example, if the EPP 2.0 data stored in the SPD states a particular memory kit is capable of running at 1800MHz with 7-7-7-20 timings at 2.0v, EPP 2.0 will automatically alter the processor's multiplier, the voltage and bus speed, along with the memory voltage, to get as close to the memory's rated speed as possible. EPP 2.0 can also be configured to overclock the processor by a user determined percentage to hit the memory's rated speed.

Broadcast and PW Short
Courtesy of the integrated NF200


When we covered the nForce 780i SLI launch a few months back, we talked about the NF200 chip that brought the chipset's support for PCI Express 2.0.  With the nForce 790i SLI, however, the NF200 has essentially been integrated into the MCP.  Along with its PCI Express 2.0 interface, NVIDIA has also disclosed details regarding patented technology that we'll talk about here.  Essentially, what NVIDIA has done is build-in a couple of fast paths inside the switch device, dedicated to optimizing mulit-GPU SLI transaction performance both back to the root CPU complex and peer-to-peer between GPUs


Specifically, there are two functional blocks as you'll note in the above diagrams, denoted as "Broadcast" and "PWShort". The Broadcast block provides a broadcast send mode for the root complex down to all GPUs in the system. This allows efficient transfer of data in one group transaction. PWShort, (which stands for Posted Write Short), is a dedicated cut-through mode for peer-to-peer communications between the GPUs, without the need to tap on upstream bandwidth to the CPU complex.  What this means is that given the right workload, Broadcast and PWShort allow for faster data transfers too and from the GPUs.

Motherboards from ASUS and EVGA

In preparation for today's launch, we got our hands on a pair of nForce 790i SLI Ultra-based motherboards, one from EVGA and another from ASUS.  As has been the case for the last few chipset releases, NVIDIA has set forth a reference motherboard that a few of their partners will be releasing.  The EVGA nForce 790i SLI Ultra pictured here is based on NVIDIA's reference design.


In addition to exposing all of the features inherent to the chipset, NVIDIA has put significant engineering efforts into the reference board to wring the most performance out of it, and to ensure it is highly overclockable.  For example, NVIDIA designed the board with tight trace lengths for better stability at high FSB speeds.  The board also has a new circular heat pipe with a larger heatsink that has more fins than previous designs for better cooling.  A new vapor chamber is attached to the circular heat pipe as well, that provides even more surface area for cooling the chipset.

Like previous high-end nForce chipsets, the nForce 790i SLI includes a removable fan that can be easily snapped into place without the need for tools or screws. The exhaust direction of the removable fan is also optimized for better overall system cooling.  Along with a well designed cooling apparatus, the reference nForce 790i SLI Ultra motherboard design also  has a number of extra ports and headers, including coaxial and optical audio connectors, an eSATA connector in the rear I/O backplane, an integrated LED POST code display, and on-board power and reset switches.


This particular package from EVGA also included a number of useful accessories like case brackets with USB, Firewire, and serial ports, a handful of SATA cables, two-way and three-way SLI bridge connectors, and the traditional user's manual, quick installation guide, and driver / utility CD.

Although it is based on the same chipset, the ASUS Striker II Extreme does not conform to NVIDIA's reference design.  Instead, ASUS designed their own motherboard around the chipset, and as usual, the company pulled no punches...


As you can see, the ASUS Striker II Extreme is built upon dark-colored PCBs with white and blue slots and connectors.  The 790i SLI SPP and MCP, and the components in the board's power array are cooled by an innovative, copper cooling apparatus, dubbed the Fusion Block System,  that's linked together via a heat-pipe and works with either air or liquid-cooling.  The Fusion Block is basically a standard chipset water-block, that happens to be linked to the other heatsinks via a heatpipe. This is a nice touch on ASUS' part that should make the Striker II Extreme more appealing to fans of liquid-cooling.


Even though the board is equipped with an oversized cooling apparatus, there is ample room around the CPU socket for large aftermarket coolers and overall the layout of the board is quite good.  All of the boards' various connectors and headers are situated around the edges of the PCB and the DIMM slots are not in-line with the first PEG slot, so installing / removing RAM is possible when a long graphics card is installed.


The ASUS Striker II Extreme ships with a broad assortment of accessories and software. Bundled with the board itself are six SATA cables, a single SATA power adapter, floppy and IDE cables, and a case bracket with additional USB and Firewire ports. In addition to these items, we also found an electro-luminescent custom, I/O shield, three thermal probes, a pack of rubber stand-offs, a baggie with wire ties, another baggie with fittings and clamps for all types of liquid-cooling systems, a user’s manual, a pack of Q-Connectors, a couple of optional fans that can be mounted to the board’s cooling apparatus, and a driver and utility DVD complete with copies of Asus' PC Probe II and AI Suite, 3DMark06 and KAV (among other things). Asus also includes a SupremeFX II audio riser card which is powered by an ADI 1988B 8-Channel HD audio codec and an "LCD Poster".

The LCD Poster is a useful  addition to the Striker II Extreme's bundle.  While it doesn't do anything extraordinary in comparison to most other LCD POST code error reporters, it is far more convenient to use.   ASUS' LCD Poster is unique in that it connects to the board via long cable and can be placed right on a desktop.  Three no need to bend down and peer into a system to read the LEDs mounted on the PCB itself – with the Striker II Extreme the error codes are clearly visible right on the LCD’s screen, wherever a user decided to mount it.

BIOS Options and Overclocking

EVGA's nForce 780i SLI Ultra motherboard, and all other reference motherboards based on the chipset for that matter, are outfitted with a Phoenix/Award BIOS designed by NVIDIA, dubbed nvBIOS.  As you'd probably expect, the BIOS is very complete and easy to navigate. From within it menus users have the ability to configure, enable or disable all of the board's integrated peripherals, and monitor voltages and clock speeds. The nForce 780i SLI Ultra also has a complete set of memory timing options that offer great flexibility for fine tuning memory performance.

The standard BIOS menu screens are somewhat ordinary, but they will give you a good feel for the layout and organization of the options, which is very good in our opinion.  Each individual screen has a host of menus that tunnel deeper and deeper as the options get more complex. Overall, it is very similar to the Award BIOS derivatives used on most other motherboards, but navigating through nvBIOS is a bit more intuitive than most.

Inspecting the BIOS
Asus and EVGA do it Right


EVGA nForce 790i SLI Ultra BIOS menus

The BIOS also gives users the ability to save profiles with different settings, which makes it easy to switch from overclocked mode, to silent mode, for example.  And it's got a built in memory test too, which is handy for testing the stability of an overclocked system.

All of the board's overclocking related options can be found under the Advanced Chipset menu.   The section is broken down into multiple sub-menus ( System Clocks, FSB & Memory Config, CPU Configuration, and System Voltages).  And each section is home to the tools necessary to tweak that particular aspect of the system.

From within the nvBIOS, users have the ability to alter CPU and HT multipliers, PCI Express, Front Side Bus, and Memory frequencies, and a number of different voltages.  CPU voltages as high as 2.0v are available and the memory voltage can be set as high as 2.275v.  All frequency and voltage settings have fine granularity and handy "current value" list that shows what each option is configured to at that point in time.  Like the nForce 680i and 780i, one of the more useful options allows users to run the memory in Linked or Unlinked mode. When linked, the memory clock is affected when the FSB is altered, like most other enthusiast class motherboards.  But in Unlinked mode, users can actually key in a memory frequency independent of the FSB.  Unlinked mode works hand in hand with EPP 2.0.  Using the Crucial memory kit we showed you on a previous page, we were able to run the RAM at 2.0GHz, without affecting the FSB using EPP 2.0 and unlinked mode.


ASUS Striker II Extreme BIOS menus

The ASUS Striker II Extreme also has a well appointed BIOS.  From within its BIOS users also have the ability to configure, enable or disable all of the board's integrated peripherals, and monitor voltages and clock speeds. The Striker II Extreme has a very complete set of memory timing options as well.

The  Striker II Extreme 's standard BIOS menu screens look much like any other enthusiast ASUS motherboard; the images here will give you a feel for the general layout and organization of the options.  Overall, other than the color scheme, they are very similar to the BIOS derivatives used on most other high-end motherboards today.  The options are also quite similar to the nvBIOS, although there are organized very differently.

It's within the "Extreme Tweaker" section of the Striker II Extreme 's BIOS that you'll find most of the board's performance tuning options.  From within the "Extreme Tweaker" section of the BIOS, users have the ability to alter clock frequencies and voltages for virtually every major on-board component. The CPU and PCI Express frequencies can be altered in 1MHz increments, and the CPU multiplier and memory ratio can also be manipulated manually.  There are also extensive voltage options for the CPU, Memory, chipset, and PLL along with 12 other voltage related options.

Overclocking the nForce 790i SLI Ultra
At the Head of the Pack

Naturally, with all of the emphasis put on the overclockability of the nForce 790i SLI Ultra, we had to give it a shot for ourselves.  Using the EVGA nForce 790i Ultra motherboard, we set out to see how high we could take the FSB before our test system became unstable.

nForce 790i SLI Ultra Overclocked: 1.97GHz Memory & FSB

There are some notes regarding the nForce 790i SLi Ultra's overclockability that we should pass on to your first though.  NVIDIA invested a lot of time into finding optimal voltages for stable overclocking and recommends leaving many BIOS options on AUTO for all but the most hardcore overclocking.  The memory configuration is also important.  For DDR3 speeds up to 1800MHz, any memory slot can be used.  But for speeds in excess of 1800MHz, NVIDIA recommends DIMMs be installed in the second pair of memory slots, in what they call an 0101 configuration.

For our tests, we installed some Crucial DDR3 RAM rated for 2.0GHz in a 0101 configuration and cranked up the CPU voltage to 1.4v and the memory voltage to 2.0v.  The rest of the motherboard's performance related options were left on AUTO.  We then increased the FSB until the system was no longer stable.  In this configuration, we were actually able to boot into Windows with the FSB and memory clocks at 2GHz (500MHz FSB), but our system wasn't completely stable. We had to back the FSB down to 493MHz.  That is an impressive number considering the minimal amount of tweaking we had to do in the BIOS and that the memory was running in linked mode.  With more extensive tweaking and fine tuning of the memory speeds, we're sure higher FSB speeds are possible as well.

Enter the GeForce 9800 GX2

As we mentioned earlier, the second new addition to NVIDIA's ultimate gaming platform is the GeForce 9800 GX2.  Although this is the first product to be released in the GeForce 9800 series, it is not based on a brand new GPU.  The GeForce 9800 GX2 is built around NVIDIA's proven G92 GPU, that first debuted on the GeForce 8800 GT.  On the GeForce 9800 GX2, however, all of the GPU's stream processors (128) are exposed, just like on the GeForce 8800 GTS 512MB.  With two GPUs powering the board, that means it has a total 256 stream processors at its disposal, in addition to 1GB of DDR3 memory - 512MB per GPU.

Due to the fact that the GeForce 9800 GX2 is built around an existing GPU, we won't delve deeply in to the GPU architecture.  We've covered the G92 and detailed its features a few previous articles, so we won't do it again here.  If you'd like to read more about the GPU specifically, we recommend perusing these three previous HotHardware articles:

NVIDIA GeForce 9800 GX2
Features and Specifications
Fabrication Process  65nm
Total Number of Transistors  1010 milltion
Core Clock (Including dispatch, texture units, and ROP units)  600MHz
Shader Clock (Stream Processors)  1500MHz
Processor Cores  256
Memory Clock (Clock Rate / Date Rate)  1000MHz / 2000MHz
Memory Interface  256-bit
Total Memory Bandwidth  128GB/s
Total Video Memory  1024MB
ROPs  32
Texture Filtering Units  128
Texture Filtering Rate  76.8 GigaTexels/sec
HDCP Support  Yes
HDMI Support  Yes
Connectors  2 x Dual-Link DVI-I, 1 x HDMI
Bus Technology  PCI Express 2.0
Form Factor  Dual Slot
Power Connectors  1 x 6-Pin, 1 x 8-Pin
Max Board Power   197 Watts
GPU Thermal Threshold  105ºC

The main features and specifications for the GeForce 9800 GX2 are listed above.  As you can see, the GPU is built using a 65nm fabrication process.  On stock GeForce 9800 GX2 cards, the GPUs are clocked at 600MHz, with a 1.5GHz shader clock, and 1GHz memory.  If you recall, the GeForce 8800 GTS 512MB's GPU is clocked at 670MHz with 900MHz memory, so a pair of GTS cards running in SLI mode will offer higher shader performance and fillrate, but less memory bandwidth.  Keep that in mind as  you look through the benchmark results that appear a little later in this article.

The GeForce 9800 GX2 offers a total of 128GB/s of memory bandwidth, with a 1GB frame buffer (512MB per GPU), 32 ROPs (16 per GPU), and  128 Texture Filtering Units (64 per GPU), for a total of 76.8GigaTexels/sec.

Not listed here are some new PureVideo HD related features that have been exposed in the G9x series of GPUs.  In addition to all of the previous PureVideo HD related features available on other GeForce graphics cards, the 9800 GX2 has support for Dynamic Contrast Enhancement, Dynamic Color Enhancement, and Dual-Stream Decode.  If you've ever corrected a digital photo's color and contrast in a program like Photoshop,  you'll be familiar with how the Dynamic Color and Contrast Enhancements work.  Each frame in a digital video is "corrected" to adjust for poor quality recording or mastering.  And the Dual-Stream Decode allows the GeForce 9800 GX2 to accelerate two video streams simultaneously, which helps reduce CPU utilization when playing back Blu-Ray or HD DVD disks that have PiP functionality.
A Closer Look at the 9800 GX2

The GeForce 9800 GX2 card is a real departure from previous NVIDIA designs.  In some respects, the GeForce 9800 GX2 is like the 7950 GX2 in that they both utilize a pair of PCBs linked together on a single graphics adapter.  The GeForce 9800 GX2, however, has a more innovative design in our opinion.  We think you'll agree after you see the goods...


With the GeForce 9800 GX2, each GPU (and its frame buffer memory) resides on its own PCB.  And sandwiched in between the PCBs is a single, large heatsink and fan that cools the GPUs and RAM.  The rear of the PCBs features a cut-out that allows air to be pulled in from either side, where it is funneled through the center of the card and ultimately exhausted from the system.  The entire assembly is encased in a metal shell that not only protects the components inside, but also helps dissipate heat.

The GeForce 9800 GX2 features a pair of dual-link DVI-I outputs in addition to an HDMI output, that also carries audio signals.  To one side of the GX2's 6-pin PCI Express power connectors, there is a tiny S/PDIF input header.  GeForce 9800 GX2 cards will include a cable that connects a motherboard's S/PDIF output to this header, where it is then channeled to the HDMI output.  And while the GX2 has a dual DVI outputs, multi-display functionality still operates like two cards - multi-GPU performance SLI mode must be disabled for a multi-monitor setup.  We should note, however, NVIDIA plans to change this with a future driver release.


If you look close, also visible on the front of the GeForce 9800 GX2, up towards the top of the retention bracket, at a pair of LEDs.  One of the LEDs will be used to indicate the primary card in a Quad-SLI configuration, while the other indicated whether or not power is properly being supplied to the card.  The GeForce 9800 GX2 requires both a 6-pin and an 8-pin PCI Express power connector to be plugged in to operate.  Because the card can consume almost 200W (197W to be exact) NVIDIA requires both types of connector - using dual 6-pin connectors will not work.  An 8-pin connector must be plugged into the card for it to operate.


Up at the top of the card you can see its SLI edge connector.  As you probably expect at this point, two of these cards can be paired up for a Quad-SLI configuration.  We'll be talking more about that in a future article, so stay tuned.

With the GeForce 9800 GX2's external shell removed, you can get a better view of the card's innards.  Along the bottom, a ribbon cable connection the two PCBs together is visible, as are the vents in the PCBs and the large cooler.  We're sure some debate will ensure as to whose dual-GPU design is more elegant, NVIDIA's or ATI's, but what does that mean really?  It's the all around performance that counts.



We've also already begin receiving full-retail GeForce 9800 GX2 cards.  What you see pictured here is the ASUS EN9800GX2.  ASUS' take on the GeForce 9800 GX2 is much like the reference design, save for the custom decal affixed to the card's enclosure.  And as usual, ASUS includes a robust accessory bundle complete with a full version of the DX10 game Company of Heroes: Opposing Fronts.  We'll be bringing you a more detailed look at this card in the not too distant future.

Our Test Systems and SANDRA

HOW WE CONFIGURED THE TEST SYSTEMS: We have two sets of benchmark tests to discuss in this article.  The first round of tests consist of five different motherboards compared using identical supporting hardware.  In addition to the motherboard tests, we also tested all of the graphics cards used in this article on either an Asus nForce 790i SLI Ultra based Striker II Extreme motherboard (NVIDIA GPUs) or an Asus P5E3 Premium (ATI GPUs) powered by a Core 2 Extreme QX6850 quad-core processor and 2GB of low-latency Corsair RAM. The first thing we did when configuring these test systems was enter their respective BIOSes and set all values to their "optimized" or "high performance" default settings. Then we manually configured the memory timings and disabled any integrated peripherals that wouldn't be put to use. The hard drive was then formatted, and Windows Vista Ultimate was installed. When the installation was complete we fully updated the OS, and installed the latest DX10 redist and various hotfixes, along with the necessary drivers and applications.

HotHardware's Test Systems
Intel and NVIDIA Powered

Hardware Used:
Core 2 Extreme QX6850 (3GHz)

Asus Striker II Extreme
(nForce 790i SLI Ultra chipset)

Asus P5E3 Premium
(X48 Express)

Radeon HD 3870 X2
GeForce 9800 GX2
GeForce 8800 GTS 512 (x2)
GeForce 8800 GTX

2048MB Corsair DDR3-1333 C7
(2 X 1GB)

Integrated Audio
Integrated Network

Western Digital "Raptor" 74GB
(10,000RPM - SATA)

Relevant Software:

Windows Vista Ultimate

NVIDIA Forceware v174.53
ATI Catalyst v8.3

Benchmarks Used:
3DMark06 v1.0.2
Unreal Tournament 3
Half Life 2: Episode 2
Enemy Territory: Quake Wars

Synthetic Benchmarks

We began our testing with SiSoftware's SANDRA XII, the System ANalyzer, Diagnostic and Reporting Assistant. We ran three of the built-in subsystem tests that partially comprise the SANDRA XII suite on the nForce 790i SLI Ultra-based system (CPU Arithmetic, Memory, and Memory Latency).  All of the scores reported below were taken with the processor running at its default clock speed of 3.0GHz with DDR3-1333MHz RAM, operating in Linked mode.



SANDRA Latency

The nForce 790i SLI Ultra performed as we expected in the SANDRA CPU arithmetic benchmark, where it was in-line with other platforms we have tested and the reference systems in SANDRA's database.  The Memory Bandwidth and Latency benchmarks, however, tell a more interesting story.  The nForce 790i SLI Ultra's peak bandwidth as reported by SANDRA is right on par, albiet slightly higher, than Intel's X38 / X48 chipset.  And the nForce 790i SLI Ultra's latency score is significantly lower than Intel's chipset as well (62ns vs. 71ns).  If these synthetic metrics hold true in real-world testing, the nForce 790i SLI should perform quite well in comparison to Intel's current offerings.

790i SLI Ultra: PCMark Vantage

We ran a handful of NVIDIA and Intel-based platforms, including the new nForce 790i SLI Ultra, through Futuremark’s latest system performance metric built especially for Windows Vista, PCMark Vantage. PCMark Vantage runs through a host of different usage scenarios to simulate different types of workload including High Definition TV and movie playback and manipulation, gaming, image editing and manipulation, music compression, communications, and productivity.  Most of the tests are multi-threaded as well, so the tests can exploit the additional resources offered by a quad-core CPU.

Futuremark PCMark Vantage
Simulated Application Performance

Looking at the individual PCMark Vantage benchmark results, its clear that the nForce 790i SLI Ultra is a high-performing chipset.  In all but one test (Communications), the new nForce- 790i SLI Ultra based motherboard from EVGA and ASUS performed at, or near, the head of the pack.  The gaming, memories, an productivity tests in particular paint the nForce 790i SLI Ultra in a very positive light.  So far, those bandwidth and latency advantages seem to be paying dividends.

790i SLI Ultra: LAME MT, Sony Vegas

In our custom LAME MT MP3 encoding test, we convert a large WAV file to the MP3 format, which is a popular scenario that many end users work with on a day-to-day basis to provide portability and storage of their digital audio content.  LAME is an open-source mid to high bit-rate and VBR (variable bit rate) MP3 audio encoder that is used widely around the world in a multitude of third party applications.

Audio Encoding

In this test, we created our own 223MB WAV file (a hallucinogenically-induced Grateful Dead jam) and converted it to the MP3 format using the multi-thread capable LAME MT application in single and multi-thread modes. Processing times are recorded below, listed in seconds. Once again, shorter times equate to better performance.

Talk about a dead heat.  Our custom LAME MT benchmark performed exactly the same on all of the platforms we tested.  This test is completely CPU bound, hence the similarities in performance between the different chipsets.

Sony Vegas
Video Rendering

Sony's Vegas DV editing software is heavily multi-threaded as it processes and mixes both audio and video streams. This is a new breed of digital video editing software that takes full advantage of current dual and multi-core processor architectures.

The nForce 790i SLI Ultra based motherboards performed very well in our Sony Vegas benchmark, trailing Intel's X48 chipset by only a second or two, but surpassing the nForce 680i SLI and 780i SLI by one to six seconds.

790i SLI Ultra: POV Ray, Kribibench

POV-Ray, or the Persistence of Vision Ray-Tracer, is an open source tool for creating realistically lit 3D graphics artwork. We tested with POV-Ray's standard included benchmarking model on all of our test machines and recorded the scores reported for each.   We should also note that we used the latest 64-bit beta build of the program.  Results are measured in pixels-per-second throughput.

Ray Tracing Performance

We had another very tight grouping in the multi-threaded POV-Ray benchmark.  It wouldn't be prudent to declare any one platform faster than another here, but the nForce 790i SLI Ultra does perform well, once again finishing just behind Intel's offering, but ahead of the previous nForces.

Kribibench v1.1
CPU-Bound 3D Rendering

For this next batch of tests, we ran Kribibench v1.1, a 3D rendering benchmark produced by the folks at Adept Development.  Kribibench is an SSE aware software renderer where a 3D model is rendered and animated by the host CPU and the average frame rate is reported.  We used two of the included models with this benchmark: a "Sponge Explode" model consisting of over 19.2 million polygons and the test suite's "Ultra" model that is comprised of over 16 billion polys.

As you can see, we had a problem getting Kribibench to perform well on the nForce 780i SLI and 680i SLI, but it had no problem on the nForce 790i SLI Ultra.  In fact, the new ASUS and EVGA nForce 790i SLI Ultra motherboard performed at the head of the pack with the Sponge Explode model.  Although, the X48 squeaked out another close one with the Ultra model.

790i SLI Ultra: Cinebench, 3DMark06 CPU

Cinebench R10 is an OpenGL 3D rendering performance test based on Cinema 4D. Cinema 4D from Maxon is a 3D rendering and animation tool suite used by 3D animation houses and producers like Sony Animation and many others.  It's very demanding of system processor resources and is an excellent gauge of pure computational throughput.

Cinebench R10
3D Rendering

This is a multi-threaded, multi-processor aware benchmark that renders a single 3D scene and tracks the length of the entire process. The time it took each test system to render the entire scene is represented in the graph below, listed in seconds.

We had another virtual dead heat in the Cinebench R10 benchmark.  All of the platforms performed within a fraction of a percentage point here, although the new nForce 790i SLI Ultras did trail the others every so slightly in the multi-threaded test.

Futuremark 3DMark06
Synthetic DirectX Gaming

3DMark06's built-in CPU test is a multi-threaded DirectX gaming metric that's useful for comparing relative performance between similarly equipped systems.  This test consists of two different 3D scenes that are processed with a software renderer that is dependent on the host CPU's performance.  Calculations that are normally reserved for your 3D accelerator are instead sent to the CPU for processing and rendering.  The frame-rate generated in each test is used to determine the final score.

It was another close on the 3DMark06 CPU benchmark.  In this test, the Intel X48 system put up the highest score, followed closely behind by the nForce 790i SLi Ultra, and the remaining nForce chipsets.

790i SLI Ultra: Gaming Tests

For our next set of tests, we moved on to some in-game benchmarking with Crysis and Enemy Territory: Quake Wars. When testing processors with Crysis or ET:QW, we drop the resolution to 800x600, and reduce all of the in-game graphical options to their minimum values to isolate CPU and memory performance as much as possible.  However, the in-game effects, which control the level of detail for the games' physics engines and particle systems, are left at their maximum values, since these actually do place some load on the CPU rather than GPU.

Low-Resolution Gaming: Crysis and ET: Quake Wars
Taking the GPU out of the Equation

The nForce 790i SLI Ultra-based EVGA and ASUS motherboard outperformed every other platform in the low-resolution Crysis CPU benchmark.  They didn't fare quite as well in the Enemy Territory benchmark, but their performance was still very good.  In the low-resolution ETQW test, the X48 put up a slightly higher framerate, but the 790i SLI Ultras did finish ahead of the older nForce chipsets.

GeForce 9800 GX2: 3DMark06

Over the next few pages, we'll focus our attention on the new GeForce 9800 GX2.  For our GPU benchmarks, we tested the GeForce 9800 GX2, and all of the other GeForces for that matter, on the ASUS Striker II Extreme.  The ATI Radeon HD 3870 X2, however, was tested on the X48-based ASUS P5E3 Premium.

Futuremark 3DMark06
Synthetic DirectX Gaming


3DMark06 is the most recent addition to the 3DMark franchise. This version differs from 3Dmark05 in a number of ways, and includes not only Shader Model 2.0 tests, but Shader Model 3.0 and HDR tests as well. Some of the assets from 3DMark05 have been re-used, but the scenes are now rendered with much more geometric detail and the shader complexity is vastly increased as well. Max shader length in 3DMark05 was 96 instructions, while 3DMark06 ups that number to 512. 3DMark06 also employs much more lighting and there is extensive use of soft shadows. With 3DMark06, Futuremark has also updated how the final score is tabulated. In this latest version of the benchmark, SM 2.0 and HDR / SM3.0 tests are weighted and the CPU score is factored into the final tally as well.

According to 3DMark06's overall score, the GeForce 9800 GX2 performs just below the Radeon HD 3870 X2, but well ahead of any single-GPU setup.  Of course, 3DMark06 performance doesn't always translate into higher performance in actual though, so we'll see how the card does in the real-world a little later.

If we tunnel into the overall 3DMark06 results, we see how each card performed in the individual Shader Model tests.  As you can see, in the SM 2.0 tests, the Radeon had a marked advantage that dwindles away in the more taxing SM 3.0 and HDR tests.

GeForce 9800 GX2: HL2 Episode 2

Half Life 2: Episode 2
DirectX Gaming Performance

Half Life 2:
Episode 2

Thanks to the dedication of hardcore PC gamers and a huge mod-community, the original Half-Life became one of the most successful first person shooters of all time.  And thanks to an updated game engine, gorgeous visual, and intelligent weapon and level design, Half Life 2 became just as popular.  Episode 2 offers a number of visual enhancements including better looking transparent texture anti-aliasing. These tests were run at resolutions of 1,920 x 1,200 and 2,560 x 1,600 with 4X anti-aliasing and 16X anisotropic filtering enabled concurrently.  Color correction and HDR rendering were also enabled in the game engine as well.  We used a custom recorded timedemo file to benchmark all cards in this test.

So much for those 3DMark06 results, huh?  In our custom Half Life 2: Episode 2 benchmark, the new GeForce 9800 GX2 significantly outperforms any other single-card solution.  The dual-card GeForce 8800 GTS 512MB SLI configuration does pull ahead due to its higher GPU core and memory clock speeds, but the difference in minscule.

GeForce 9800 GX2: Unreal Tournament 3

Unreal Tournament 3
DirectX Gaming Performance

Unreal Tournament 3

If you're a long-time PC gamer, the Unreal Tournament franchise should need no introduction.  UT's fast paced action and over the top weapons have been popular for as long as Epic has been making the games.  For these tests, we used the latest addition to the franchise, Unreal Tournament 3.  The game doesn't have a built-in benchmarking tool, however, so we enlisted the help of FRAPS here.  These tests were run at resolutions of 1,920 x 1,200 and 2,560 x 1,600 with no anti-aliasing or anisotropic filtering enabled, but with the UT3's in game graphical option set to their maximum, with color correction enabled.

The Radeon HD 3870 X2 puts up a good fight with UT3 running at 1920x1200, but the GeForce 9800 GX2 pulled away once the resolution was increased to 2560x1600.  At the higher resolution, the GeForce 9800 GX2 was over 10 FPS faster than the 3870 X2, and nearly twice as fast as any of the single-GPU powered cards.

GeForce 9800 GX2: ET Quake Wars

Enemy Territory: Quake Wars
OpenGL Gaming Performance

Enemy Territory:
Quake Wars

Enemy Territory: Quake Wars is Based on id's radically enhanced Doom 3 engine and viewed by many as Battlefield 2 meets the Strogg, and then some.  In fact, we'd venture to say that id took EA's team-based warfare genre up a notch or two.  ET: Quake Wars also marks the introduction of John Carmack's "Megatexture" technology that employs extremely large environment and terrain textures that cover vast areas of maps without the need to repeat and tile many small textures.  The beauty of megatexture technology is that each unit only takes up a maximum of 8MB of frame buffer memory.  Add to that HDR-like bloom lighting and leading edge shadowing effects and Enemy Territory: Quake Wars looks great, plays well and works high end graphics cards vigorously.  The game was tested with all of its in-game options set to their maximum values with soft particles enabled in addition to 4X anti-aliasing and 16x anisotropic filtering.

The new GeForce 9800 GX2 continued its beat-down of all the other graphics cards in our custom Enemy Territory Quake Wars benchmark.  The dual-card GeForce 8800 GTS 512MB SLI configuration was slightly faster, but none of the other cards - including the dual-GPU powered Radeon HD 3870 X2 - could touch the GeForce 9800 GX2 here.

GeForce 9800 GX2: Crysis

Crysis v1.2
DirectX 10 Gaming Performance


If you're at all into enthusiast computing, the highly anticipated single player, FPS smash-hit Crysis, should require no introduction. Crytek's game engine visuals are easily the most impressive real-time 3D renderings we've seen on the computer screen to date.  The engine employs some of the latest techniques in 3D rendering like Parallax Occlusion Mapping, Subsurface Scattering, Motion Blur and Depth-of-Field effects, as well as some of the most impressive use of Shader technology we've seen yet.  In short, for those of you that want to skip the technical jib-jab, Crysis is HOT.  We ran the SP demo with all of the game's visual options set to 'High' to put a significant load on the graphics cards being tested.

With Crysis running at 1920x1200, the GeForce 9800 GX2 simply crushes the competition, with the exception of the GTS SLI setup.  At 2560x1600, however, the scaling isn't quite as dramatic.  We should note that we had an issue with the Radeon HD 3870 X2 at the higher resolution and have omitted its results.

GeForce 9800 GX2: Video Performance

We also did some quick testing of the GeForce 9800 GX2's video processing engine, in terms of both image quality and CPU utilization with some HQV and H.264 playback tests.

Video Playback Performance: SD and HD
HQV and H.264

HQV is comprised of a sampling of SD video clips and test patterns that have been specifically designed to evaluate a variety of interlaced video signal processing tasks, including decoding, de-interlacing, motion correction, noise reduction, film cadence detection, and detail enhancement. As each clip is played, the viewer is required to "score" the image based on a predetermined set of criteria. The numbers listed below are the sum of the scores for each section. We played the HQV DVD using the latest version of Cyberlink's PowerDVD HD, with hardware acceleration for AMD AVIVO HD and NVIDIA PureVideo HD extensions enabled.

Both ATI's and NVIDIA's latest GPUs have no trouble with SD video playback.  The Radeon HD 3870 X2 and GeForce 9800 GX2 put up near perfect scores in the HQV test.  In case you're not familiar with HQV, 130 points is the maximum score attainable.  At 128 points, a PC equipped with either of these graphics cards plays back DVD video at quality levels better than the vast majority of set-top DVD players on the market.

Next we conducted a test using an H.264 encoded movie trailer clip for "Beowulf" which is available for download on Apple's QuickTime HD website.  The CPU utilization data gathered during these tests was taken from Windows Vista's built-in Performance Monitor. The graphs show the CPU utilization for a GeForce 9800 GX2 and a Radeon HD 3870 X2 using PowerDVD HD to playback the QuickTime clip.

GeForce 9800 GX2

Radeon HD 3870 X2

With a powerful quad-core processor at the heart of our test system and an unencrypted HD video clip being played back, both the GeForce 9800 GX2 and Radeon HD 3870 X2 averaged low, single-digit CPU utilization in this test.  We should note that with hardware acceleration disabled, playing this video clip results in about 12% - 15% average CPU utilization, so there is a marked improvement with both PureVideo HD and UVD.  Also note that with encoded content, like an off the shelf Blu-Ray disc for example, CPU utilization will be measurably higher that what you see here, however, both platforms should have no trouble playing back the video.

Power Consumption and Noise

Before we bring this article to a close, we'd like to cover a few final data points. Throughout all of our benchmarking and testing, we monitored how much power our test systems were consuming using a power meter. Our goal was to give you all an idea as to how much power each configuration used while idling and under a heavy workload. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the motherboards alone.

Total System Power Consumption
Tested at the Outlet

This first graph shows the power consumption of each motherboard, when outfitted with identical supporting hardware (Core 2 Extreme QX6850, 2GB RAM, GeForce 8800 GTX).  The nForce 790i SLI Ultra based motherboard consumed the most power here, especially under load where the ASUS Striker II Extreme used more power than even the 3-chip nForce 780i SLI.

This next graph represent the total system power consumption with the different graphics cards installed.  While idling, the Radeon HD 3870 X2-powered system consumed the least amount of power, but under load the Radeon shot up to near the head of the pack; only the GeForce 8800 GTS 512MB SLI configuration consumed more.  If you focus our attention on the GeForce 9800 GX2 specifically, you'll see that despite being powered by two GPUs and 1GB of RAM, the GX2 consumes only slightly more power than the GTX.

Finally, we'd like to comment on the GeForce 9800 GX2's noise level.  While at the Windows desktop or during light gaming, the GeForce 9800 GX2 is near silent.  In a typical system, we doubt the card will be audible over the average CPU cooler or PSU fan.  When running under a heavy workload, however, the GX2's fan does spin up to an audible level, but we don't consider the card to be loud at all.  And it doesn't product any annoying high-pitched whine either.

Our Summary and Conclusion

Performance Summary: We'll need to discuss the individual performance of two products here, the nForce 790i SLI Ultra chipset and the GeForce 9800 GX2 graphics card; so we'll break down this summary into two sections.

According to our testing of two full-retail motherboards from ASUS and EVGA, the nForce 790i SLI Ultra's performance is top notch.  In all of our tests, the nForce 790i SLI Ultra finished at or near the top of the charts.  PCMark Vantage in particular reported strong performance for the nForce 790i SLI Ultra, as did a couple of the SiSoft SANDRA tests.  All of the real-world application benchmarks also reported strong performance.

As for the GeForce 9800 GX2, it is clearly the most powerful single graphics adapter currently available.  In all of our in-game benchmarks, the GeForce 9800 GX2 outpaced every other single graphics card configuration including the Radeon HD 3870 X2.  It was only in 3DMark06 that the Radeon had an advantage, but that didn't translate into any benchmark wins with actual games at the high resolutions we tested.

The NVIDIA nForce 790i SLI Ultra chipset and GeForce 9800 GX2 are very strong products.  It took a while for NVIDIA to revamp their entire ultimate PC gaming platform, but they have finally done it, and have done it well.  The nForce 790i SLI Ultra chipset has a great feature set, it's highly overclockable, and performance was top notch.

The GeForce 9800 GX2 is also feature-rich, with support for HDMI and new PureVideo HD capabilities, and its performance is excellent as well.  As we pointed out in our evaluation of the Radeon HD 3870 X2, the ultimate performance of multi-GPU cards like the X2 and GeForce 9800 GX2 will be determined by how well the card’s drivers scale in a particular game.  If a new game hits store shelves and the drivers don’t recognize the executable, they will perform much like a single-GPU card that is roughly half the price.   We're sure NVIDIA's driver team will try to minimize this situation, but it will be an issue at some point in time, no matter how hard they work.  If history is an indicator, however, NVIDIA is poised to handle this situation well, and now that their flagship graphics card is powered by two GPUs, we're sure a stronger than usual focus will be made on multi-GPU scaling.

Actual street prices for the nForce 790i SLI Ultra and GeForce 9800 GX2 remain to be seen, but NVIDIA has set the MSRP of the GX2 at $599 - $649 and motherboards based on the nForce 790i SLI Ultra reference design should arrive in the $350 price range.  ASUS' Striker II Extreme, however, has an MSRP of $469, and we suspect a few other non-reference nForce 790i SLI Ultra-based boards will be pricey as well.  790i SLI Ultra based boards are expected arrive this month, with follow up 790i SLI non-Ultra and 750i SLI-based products slated to arrive in the April timeframe. GeForce 9800 GX2 cards should be available immediately.
There you have it.  NVIDIA has unveiled their next wave of flagship products and redefined the high-end in PC gaming hardware.  And they're not done yet, nor are we.  We've still got to cover Quad-SLI technology and a new high-end single-GPU based graphics card is in the works as well, so stick around.

 NVIDIA nForce 790i SLI Ultra

NVIDIA GeForce 9800 GX2

Update: NewEgg has already listed GeForce 9800 GX2 cards from EVGA, PNY, BFG, XFX, and Zotac.  And all are priced at $599.

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