ATI CrossFire Technology Showcase

Introduction, Specs. & Related Info

When ATi announced their new CrossFire multi-GPU rendering technology months ago, it could have been viewed by many enthusiasts and the market as more of a reactionary response to NVIDIA's SLI multi-GPU technology than anything else.  When our preview showcase article was posted, hardware was still months away from being a reality and since then, only bits and pieces have leaked out on performance expectations.  Regardless, what looked good then on paper, certainly needed to be taken with a grain of salt and a dash of skepticism, since frankly no one could be certain of product performance claims without hardware in hand.  All the while, NVIDIA's SLI product offering and the all-important drivers that back it up, have been maturing and expanding breadth in support for virtually all game titles on the market now, through either predefined game profiles or user customized settings.

We were recently whisked away to sunny California for an Editor's Day press event to see ATi's next generation GPUs in action, but the week before we hit the road a Radeon X850 XT CrossFire kit was shipped to us from ATi for evaluation.  With an NDA lift date only a couple of short weeks away, the crunch was on, since the better part of one of those weeks was spent behind closed doors with ATi.

ATI Radeon X850 XT & CrossFire / Radeon XPress 200
Features & Specifications

ATI Radeon X850 XT Platinum Edition
_500MHz engine
_.13 micron copper low-k
_1GHz memory data rate
_256-bit memory interface
_256MB GDDR3 memory
_16 pixel pipes
_6 vertex pipes
_8 Gigapixel/second fill rate
_32 GB/s Peak Memory Bandwidth
_HYPER Z support for HD resolutions including Hierarchical Z, color and Z compression
_Hierarchical Z and Early Z
_Z Compression
_Fast Z Clear
_Z/Stencil Cache

Six Vertex Engines
_Workstation class vertex processing power
_600 million polygon transforms per second
_5.7 billion vertex shader operations per second
_Workstation-class performance

High-detail Geometry
_Designed for next-gen games with massive polygon counts
_Allows huge numbers of characters on screen at once
_High definition foliage and particle effects

Smart Shader HD
_Long pixel shaders
_1536 instructions per pass
_High-detail geometry shaders
_Infinite length shaders (multipass via F-buffer)
_Single pass trig functions (Sine & Cosine)

3Dc Compression Technology
_Lossless Normal Map Compression
_4:1 Normal Map Compression technology

SmoothVision HD
_Sparse sample pattern AA with gamma correction
_Temporal AA (up to 12X effective)
_Centroid AA
_16X Anisotropic filtering with adaptive heuristics

HyperZ HD
_Optimized for performance at high display resolutions, including HDTV resolutions
_Lossless z-buffer compression (up to 48:1)
_Rejects up to 256 occluded pixels per clock
_Up to 32 Z/stencil operations/clock

VideoShader HD
_High-quality video processing & acceleration
_Real-time user programmable video effects
_Video post processing and filtering
_MPEG 1, 2, 4 encode and decode acceleration
_FULLSTREAM Video Deblocking
_WMV9 decode acceleration
_High-quality resolution scaling
_Adaptive Per Pixel Deinterlacing
_Motion Compensation
_Noise removal filtering
_Display Rotation

The following dynamic rendering modes are available:
SuperTiling - CrossFire renders alternate 32x32 pixel squares in a fine-grained checkerboard pattern. This configuration increases
image-rendering quality, as each card processes half of the complex 3D objects in the pixel squares.

Scissor Mode - each graphics card renders up to half of the display, either vertically or horizontally depending on the game or

Alternate Frame Rendering - the two graphics cards are used to render alternate frames of the display. This configuration increases the detail of the 3D objects each card can render, as each card handles half of the total number of frames.

Super Anti-aliasing - improves image quality by combining the results of full-screen anti-aliasing across two graphics cards in a
CrossFire™ configuration. The two graphics cards work on different anti-aliasing patterns within each frame.

RADEON XPRESS 200 Crossfire Edition
_ATI's first discrete PCI Express chipset for AMD K8 platforms
_Offers flexible platform design options for the mainstream and enthusiast markets
_Pin and BIOS compatible with onboard graphics platform

Security and Reliability:
_TPM 1.1 & 1.2 support
_Improved security and authentication for:
_File storage, e-mail and personally identifiable information
_Remote Access and data decryption
_Broadcom enhanced Gigabit Ethernet w/ TPM
_Standards based TPM security for corporate networks
_RAID 1 support
_Higher date security with built in fault tolerance
_Improved capacity and performance
_AMD integrated enhanced Virus Protection technology

_Full support for Gigabit Ethernet and 10/100
_Gigabit Ethernet supported via PCI Express
_ATI provides increased flexibility for partners
_Choice of provider
_Cost savings for implementation
_Leading edge technology
_Best of breed partners ensure ATI can deliver the latest and fastest networking solutions on the market today (Marvell & Broadcom)
_Integrated GbE offers no performance or cost advantage different anti-aliasing patterns within each frame.

ATI Radeon X850 XT


The ATi Cross Fire solution we'll be testing today consists of the following three main components, an ATi CrossFire Edition "master" Radeon X850 XT card, an ATi Radeon Xpress 200 CrossFire Edition chipset based reference design motherboard, and a second ATi Radeon X850 XT standard graphics card.  We've actually covered all of these platform technologies in previous HotHardware articles and invite you to scan through them now for a quick refresher course.

So again, the current requirements for a CrossFire setup are, as with NVIDIA's SLI, a completely proprietary solution.  That is to say, today you need a Radeon Xpress 200 CrossFire Edition board if you want to run a pair of ATi cards in CrossFire mode.  We have however, also confirmed that ATi will support Intel's i955X chipset for CrossFire eventually and have even heard rumblings from a few folks that nForce 4 support could be on the way as well, but for now and for what we have to work with today it's all ATi.  Certainly there are no limitations in hardware, with the PCI Express implementations that are found with any of these chipsets, but cross-platform characterization and compatibility in this area is a major undertaking.  Without question, if ATi can pull this off, it will obviously expand the market opportunity for CrossFire significantly and certainly allow them to take on NVIDIA with a bit more punch.

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