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AMD Phenom II X4 955 Black Edition Processor
Date: Apr 23, 2009
Author: Marco Chiappetta
Introduction and Specifications


Over the course of a few months in late 2007 and early-to-mid 2008, AMD unveiled their Spider platform, consisting of AMD-built desktop processors, chipsets, and graphics cards, and refreshed said platform with faster processors and graphics cards. Fast forward to today, and AMD is doing the same thing, but this time with the newer, more powerful Dragon platform. It's like Déjà Vu all over again, as they say.

Even though some components have been available for much longer, the complete Dragon platform--consisting of Radeon HD 4000 series graphics, 7-series chipsets, and Phenom II processors--has been around since January of this year, when the Phenom II first arrived. Since the initial launch, AMD has updated the GPU portion of the platform with the excellent Radeon HD 4890, i.e. RV790, and introduced mainstream socket AM3 processors. And today, AMD ups the ante yet again with the highest clocked quad-core CPU to be offered by the company to date, the 3.2GHz Phenom II X4 955 Black Edition.

We've got one of AMD's new flagship desktop processors in house for a little benchmark action and have clocked it down to 3.0GHz as well to simulate the performance of the Phenom II X4 945, which is also arriving alongside the 955 BE. Read on for the full scoop...

AMD Phenom II X4 955 Black Edition Processor

AMD Phenom II X4 Processors 
Specifications and Features

Model / Processor Frequency: AMD Phenom II Processor Model X4 955 (3.2GHz) / 945 (3.0GHz)
L1 Cache Sizes: 64K of L1 instruction and 64K of L1 data cache per core (512KB total L1 per processor)
L2 Cache Sizes: 512KB of L2 data cache per core (2MB total L2 per X4 processor)
L3 Cache Size (shared): 4MB
Memory Controller Type: Integrated 128-bit wide memory controller, capable of being configured for dual 64-bit channels for simultaneous read/writes
Memory Controller Frequency: Up to 2.0GHz with Dual Dynamic Power Management
Types of Memory: Unreg. DIMMs up to PC2 8500 (DDR2-1066MHz) and PC3 1333 (DDR3-1333MHz)
HyperTransport 3.0: One 16-bit/16-bit link @ up to 4000MHz full duplex
Total Processor Bandwidth: Up to 33.1 GB/s bandwidth
Packaging: Socket AM3 938-pin organic micro pin grid array (micro-PGA) (backward compatible with Socket AM2)
Fab location: GLOBALFOUNDARIES Fab 1 module 1 Dresden, Germany
Process Technology: 45nm (.045-micron) DSL Silicon on Insulator (SOI)
Approximate Transistor count: approx. ~758 million (65nm)
Approximate Die Size: 258 mm2 (45nm)
Nominal Voltage: .0875-1.5 Volts
Max Ambient Case Temp: 62 degress Celsius
Max TDP: 125 Watts
*Note: MC configurable for dual 64-bit channels for simultaneous read/writes
**Note: for DDR3-1333, AM3 boards will support 1-DIMM-per-channel @ 1333MHz

As most of you probably know, and we've already mentioned, the Dragon platform as a whole is not new. Most of its core components have already been on the scene for quite some time now. As such, we have already covered them in-depth here on HotHardware in previous articles, so we won't do the same again here. We will, however, recommend that you take a look at a few recent articles to get familiar with some of the underlying technology and components that comprise AMD's Dragon platform.

The Radeon HD 4800 series articles detail the features and technology that have made the GPUs so successful in the 3D graphics space. And the various 7-series chipset, Phenom, Phenom II and Athlon processor, and Spider platform related articles cover the remainder of the platform specifics--with the exception of the new Phenom II 945 and 955 being announced today that is...

Vital Signs and the new PIB Cooler

As we've already mentioned, we've got one of AMD's brand new Phenom II X4 955 Black Edition processors in-house for testing. Like its predecessors, this new chip looks just like the original Phenoms, due to its use of similar packaging and heat spreader designs. Here's what the CPU looks like "in the flesh" so to speak.

Socket AM3 Phenom II X4 955 Black Edition

Like the Phenom II X4 810 and X3 720 BE that were introduced a few months back, the Socket AM3 Phenom II X4 955 is architected to work with both DDR2 and DDR3 memory types, and with Socket AM3 or AM2+ motherboards.  Socket AM2+ processors do not have the ability to work with DDR3 though, so AMD made some changes to the Socket AM3 pin configuration to prevent AM2+ processors from being plugged into AM3 sockets.  Socket AM3 processors like the 955 BE pictured above have 938 pins, whereas socket AM2 processors have 940; two pins have been removed.  If you look close at the shot of the processor's underside above, you'll notice that there are two groups of three and two groups of two pins missing on the underside of the Phenom II X4 955 Black Edition--on AM2+ processors, four groups of two pins are removed.  Keying the processors and sockets this way prevents AM2+ processors from being installed on AM3 motherboards, but allows AM3 processors to be installed on either type of motherboard.

AMD's New PIB CPU Cooler

In addition to launching a pair of new processors today, AMD is also unveiling a new PIB (processor in box) heatsink design. The new heatsink which will be included with these, and future, Phenom II processors features a compact design, with a copper base and heat-pipes, that feed into an array of aluminum fins. An 80mm AVC fan sits atop the assembly, which shoots air downward, toward the base. We used the new heatsink throughout all of our testing and found it to be a relatively capable cooler. It is not silent, but the fan on the unit isn't loud by any means, even when running at full bore. And performance is good for a "stock" cooler, as you'll see in the overclocking section on the next page. The new AMD PIB cooler won't compete with today's high-end air coolers, but potential consumers thinking about making the move to an AM3 CPU can rest assured the stock cooler does its job quite well.

AMD Phenom II X4 955 Black Edition CPU-Z Details

To get a closer look into the Phenom II 955 Black Edition's inner workings, we fired up CPU-Z to take a peek at its core and cache configurations. CPU-Z correctly identifies the processor as Phenom II X4 based on the core codenamed "Deneb", but incorrectly identifies it as an AM2+ CPU (we had it installed in an AM3 motherboard). As the information shows, the chips are manufactured using AMD's 45nm process technology and our particular sample has a stepping designation of 2 and core revision of RB-C2. The Phenom II X4 955 BE chip is clocked at 3.2GHz, due to its 16x multiplier and 200MHz base clock, the HT link is running at 2.0GHz, and there is 512K of L1 Data / Instruction cache, 2MB of L2 cache (512K per core), and 6MB of shared L3 cache available.

Overclocking and Overdrive 3.0

By now, we suspect that most of you have heard about the significant overclocking headroom left in AMD's latest Phenom II processors. In a previous article, we were able to achieve clock speed increases of about 800MHz over stock with the Phenom II X3 720 Black Edition; other Phenom IIs we tested didn't fare quite so well, but 600MHz to 700MHz increases were not uncommon using nothing but the stock air cooler. 

Overclocking The Phenom II X4 955
Pedal To The Metal

AMD Phenom II X4 955 Black Edition Overclocked to 3.72GHz

With our previous success in mind, we set out to overclock the new Phenom II X4 955 Black Edition using the stock PIB cooler we showed you on the previous page and an Asus 790FX based motherboard. With a bump in CPU core voltage to 1.5v, we were able to take the Phenom II X4 955 Black Edition to just over 3.7GHz with complete stability--only a 500MHz increase. 3.8GHz - 4GHz would load Windows, but no amount of voltage allowed us to maintain stability. Remember, Black Edition processors are unlocked, so we were able to achieve this overclock by merely altering the CPU multiplier and voltage in the system BIOS or via AMD's OverDrive utility. As you can see in the screencap above, while overclocked, the 955 BE hummed along at a toasty 70'C+. That's a bit to warm for our liking, but keep in mind we were using the stock cooler. While idling, the chip barely broke the 35'C barrier.

AMD OverDrive 3.0

We'd also like to show you a new version of the OverDrive utility AMD is prepping for release. OverDrive 3.0 as it is known offers all of the features of previous versions of the tool, in addition to fan speed controls, Black Edition Memory Profiles, and new smart application profiles. Fan speed control is self-explanatory. Black Edition Memory Profiles, however, require some explanation. Like EPP or XMP, BEMP polls the SPD in certain high-frequency DDR3 memory modules and applies the intended frequency and latency settings from within AOD 3.0. The feature requires BIOS support, and at this time, only a few memory kits are compatible with the feature. Those kits include:

  • Corsair: CM3X2G1600C9DHX
  • Kingston: KHX11000D3LLK2/2G and KHX12800D3K2/2G
  • Mushkin: 991629
  • OCZ: OCZ3AMD18002G

Which brings us to the smart application profiles. The smart profiles tool gives users the ability to alter system parameters on a per-application basis to either increase performance, like in games or content creation applications, or to lower power utilization, say while playing back digital media files.

Test Systems and SANDRA


How We Configured Our Test Systems: When configuring our test systems for this article, we first entered their respective system BIOSes and set each board to its "Optimized" or "High performance Defaults". We then saved the settings, re-entered the BIOS and set the memory timings for each platform manually. The hard drives were then formatted, and Windows Vista Ultimate SP1 was installed. When the Windows installation was complete, we fully updated the OS, and installed the of the drivers necessary for our components. Auto-Updating and Windows Defender were then disabled and we installed all of our benchmarking software, defragged the hard drives, and ran the tests.

 HotHardware's Test Systems
 Intel and AMD - Head To Head 

System 1: 
AMD Phenom II X4 810
(2.60GHz Quad-Core)
AMD Phenom II X3 720BE
(2.8GHz Tri-Core)

AMD Phenom II X4 940
(3.0GHz Quad-Core)

Asus M4A79T Deluxe
(AMD 790FX Chipset)

2x2GB Corsair DDR3-1600

CL 7-7-7-20 - DDR3-1333

GeForce GTX 280
On-Board Ethernet
On-board Audio

WD150 "Raptor" HD
10,000 RPM SATA

Windows Vista Ultimate

NVIDIA Forceware v180.43
DirectX Redist (August 2008)

System 2: 
Core 2 Duo E6850
(3.0GHz - Quad-Core)

Core 2 Quad Q9400
(2.66GHz - Quad-Core)

Asus P5E3 Premium
(X48 Express Chipset)

4x1GB Corsair DDR3-1600
CL 7-7-7-20 - DDR3-1333

GeForce GTX 280
On-Board Ethernet
On-board Audio

WD150 "Raptor" HD
10,000 RPM SATA

Windows Vista Ultimate
NVIDIA Forceware v180.43
DirectX Redist (August 2008)

System 3:
Core i7 920
(2.66GHz - Quad-Core)

Intel DX58SO
(X58 Express Chipset)

3x1GB Qimonda DDR3-1066
CL 7-7-7-20 - DDR3-1066

GeForce GTX 280
On-Board Ethernet
On-board Audio

WD150 "Raptor" HD
10,000 RPM SATA

Windows Vista Ultimate
NVIDIA Forceware v180.43
DirectX Redist (August 2008)

 Preliminary Testing with SiSoft SANDRA 2009
 Synthetic Benchmarks

We began our testing with SiSoftware's SANDRA XII, the System ANalyzer, Diagnostic and Reporting Assistant. We ran four of the built-in subsystem tests that partially comprise the SANDRA 2009 suite with AMD's new Phenom II X4 955 Black Edition processor (CPU Arithmetic, CPU Multimedia, Memory Bandwidth, and Cache and Memory).  All of the scores reported below were taken with the processor running at its default clock speed of 3.2GHz, with 4GB of DDR3-1333 RAM running in unganged mode.

Phenom II X4 955 BE
CPU Arithmetic

Phenom II X4 955 BE

Phenom II X4 955 BE
Mem. Bandwidth:

Phenom II X4 955 BE
Cache: DDR3-1333

The Phenom II X4 Black Edition performed very well in the sampling of synthetic SiSoft SANDRA tests that we ran. The chip obviously outran every other AMD-built CPU by a fair margin and it hung in there with similarly clocked Penryn-based Core 2 processors, although Intel did have the edge overall. The Core i7 920 held onto sizable leads in most tests, except for the integer portion of the Multimedia benchmark where AMD's new flagship took the top spot.

PCMark Vantage

We ran a handful of processors and platforms, including the new Phenom II X4 955 BE and 945, 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 workloads 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

The Phenom II X4 955 Black Edition performed very well in PCMark Vantage. Overall, it was obviously the fastest of all of the AMD processors we tested and in a few tests it even outperformed the Core i7 920. The Core i7 920 maintained an overall lead, however, and in the gaming test it simply couldn't be touched.

LAME MT and Kribibench

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.

LAME MT can support of maximum of only two threads, hence the X3's strong performance versus the lower-clocked quad-cores here. Once again, the new Phenom II processors perform well, albeit just a bit shy of the Intel-based competition.

The Phenom II X4 955 Black Edition outruns all of the other AMD-made processors in our custom LAME MT encoding benchmark, but can't quite keep pace with the Core i7 920 or similarly clocked Core 2 Quad.

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 in which 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.

Once again, thanks to its higher clock speed, the Phenom II X4 955 BE outpaced all other AMD processors, but the Core 2 Quads and Core i7 still maintain a solid lead in this test.

Cinebench R10 and 3DMark06

Cinebench R10 is an OpenGL 3D rendering performance test based on Cinema 4D from Maxon. Cinema 4D 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 rate at which each test system could render the entire scene is represented in the graph below.

Clock for clock, its clear that the Intel-powered rigs have a distinct advantage in this test.  The Phenom IIs perform well though, and again we see the Phenom II X4 955 Black Edition outrun the other AMD processors.

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.

The Phenom II X4 955 Black Edition performs very well in the 3DMark06 CPU benchmark, but it couldn't catch the similarly clocked Core 2 Extreme; the Core i7 only increases Intel's lead here.

Gaming: Crysis and F.E.A.R.

For our next set of tests, we moved on to some in-game benchmarking with Crysis and F.E.A.R. When testing processors with Crysis or F.E.A.R., 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 F.E.A.R.
Taking the GPU out of the Equation

The Intel processors have a distinct advantage in our Crysis testing, where the Core 2 Quads and Core i7 maintain solid leads. But in F.E.A.R. the tables turn considerably and AMD's new baby takes the top spot.

Power Consumption

We'd like to cover a few final data points before bringing this article to a close. Throughout all of our benchmarking and testing, we monitored how much power our test systems consumed using a power meter. Our goal was to give you all an idea as to how much power each configuration used while idling and while 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 processors alone.

Total System Power Consumption
Tested at the Outlet

Although AMD rates the new Phenom II X4 955 BE and 945 at the same 125 watts, in our testing, we found them to consume less power than the X4 940 under load. At idle, however, the 955 and 945 used a bit more power than their DDR2-based counterpart. We should note, however, that changes in the test platform (the Phenom II X4 940 had to be tested on an AM2+ motherboard with DDR2 RAM) could account for some of the differences in power consumption seen here.

Our Summary and Conclusion

Performance Summary: When we evaluated the Phenom II X4 920 and 940 processors upon their release back in January, we said this in our performance summary, "The new Phenom II X4 920 and 940 are easily the most powerful desktop processors released from AMD to date. They performed well throughout our entire battery of benchmark tests, besting AMD's previous flagship CPU...virtually across the board." Those words were true then, and with the release of the higher-clocked 3.2GHz Phenom II X4 955 Black Edition and 3.0GHz X4 945, they are true now. These two new processors are the most powerful desktop products to be released by AMD to date. Performance in every application was very good, as should be expected from a high-end quad-core processor, but as our tests have shown Intel still has a performance edge overall.

AMD has released some mighty interesting processors as of late. The inexpensive tri-core Phenom II X3 720 Black Edition generated quite a bit of buzz upon its release, due to its excellent value and overclockabilty. And it didn't hurt that a few weeks later news broke showing that some 720 BE processors could be modded into quad-cores with a simple BIOS tweak. The Phenom II 720 Black Edition was clearly a strong product in AMD's mainstream CPU line-up. The new Phenom II X4 955 Black Edition and X4 945, however, take things up a notch at the high-end of AMD's product stack, and like the Phenom II X3 720 Black Edition, they do so without breaking the bank.

The Phenom II X4 955 Black Edition and the X4 945 will be available immediately for $245 and $225, respectively (the 955 BE has already popped up on NewEgg). Pair one of these processors with an enthusiast-class 790FX or GX-based socket AM3 motherboard and 4GB of DDR3-1333 memory and you've got the makings of a powerful desktop platform for about $450. That's not exactly cheap, but considering the performance and overclockability of the platform, it certainly represents a good value. Yes, Intel's similarly clocked Core 2 Quads and Core i7 processors staill maintain a performance advantage, but there is no denying that AMD's Dragon platform is an attractive option that has only been enhanced by the introduction of these new CPUs.



  • Strong Performance
  • Good Power Consumption
  • Great Upgrade Path
  • DDR2 or DDR3 Compatible
  • Overclockable
  • Competitive Pricing
  • Fastest AMD CPUs to Date


  • Still Nipping At intel's Heals

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