ATI Radeon HD 4850 Single and CrossFire Mode Review

            After numerous hurdles in getting their 2900 line of cards out, in finally catching up to Nvidia in getting a DX10 card out even if it was one that was too hot and didn't perform well, ATI managed a significant comeback late last year with the 3000 Radeon series of cards especially the 3870X2, 3870, and 3850. Performance increased dramatically able to compete with Nvidia, price, and power consumption. But Nvidia has come back first with the 9800 GTX then the incredibly expensive GTX 280. And what does AMD have to bounce right back but the brand new Radeon HD 4850 launching today and in a few weeks the Radeon HD 48 4870 which should topple the GeForce 9800 GTX. Below is the shot of the actual card we used from our friends at Visiontek.  We received two cards from the trip to the launch in San Francisco and some other goodies have since arrived in Austin.  Or across town at least.   Time is one thing that is not on our side as ATI pushed the NDA expiration ahead a week as cards have already started to flood the channel making the time for the review very tight. We'll cut straight to the chase here and give you the specs. The gist of it is this is a second generation 55nm Radeon product and the 4000 series brings some amazing gains in stream processor count and efficiency.   ATI Radeon HD 4850 ATI Radeon HD 3870 Manufacturing Process 55nm 55nm Stream Processors 800 320 Texture Units 40 16 Render Back-Ends 16 16 Core Clock Speed 625Mhz 775MHz Memory Data Rate 2.0 Gbps GDDR3 2.25 Gbps GDDR4 Math Processing Rate (multiply-add) 1.0 TeraFLOPS .497 TeraFLOPS DirectX Support 10.1 10.1   The MSRP for the Radeon HD 4850 will be $199. 956 million transistors on 55nm fabrication process PCI Express 2.0 x16 bus interface 256-bit GDDR3/GDDR5 memory interface Microsoft® DirectX® 10.1 support Shader Model 4.1 32-bit floating point texture filtering Indexed cube map arrays Independent blend modes per render target Pixel coverage sample masking Read/write multi-sample surfaces with shaders Gather4 texture fetching Unified Superscalar Shader Architecture 800 stream processing units Dynamic load balancing and resource allocation for vertex, geometry, and pixel shaders Common instruction set and texture unit access supported for all types of shaders Dedicated branch execution units and texture address processors 128-bit floating point precision for all operations Command processor for reduced CPU overhead Shader instruction and constant caches Up to 160 texture fetches per clock cycle Up to 128 textures per pixels Fully associative multi-level texture cache design DXTC and 3Dc+ texture compression High resolution texture support (up to 8192 x 8192) Fully associative texture Z/stencil cache designs Double-sided hierarchical Z/stencil buffer Early Z test, Re-Z, Z Range optimization, and Fast Z Clear Lossless Z & stencil compression (up to 128:1) Lossless color compression (up to 8:1) 8 render targets (MRTs) with anti-aliasing support Physics processing support Dynamic Geometry Acceleration High performance vertex cache Programmable tessellation unit Accelerated geometry shader path for geometry amplification Memory read/write cache for improved stream output performance Anti-aliasing features Multi-sample anti-aliasing (2, 4 or 8 samples per pixel) Up to 24x Custom Filter Anti-Aliasing (CFAA) for improved quality Adaptive super-sampling and multi-sampling Gamma correct Super AA (ATI CrossFireX? configurations only) All anti-aliasing features compatible with HDR rendering Texture filtering features 2x/4x/8x/16x high quality adaptive anisotropic filtering modes (up to 128 taps per pixel) 128-bit floating point HDR texture filtering sRGB filtering (gamma/degamma) Percentage Closer Filtering (PCF) Depth & stencil texture (DST) format support Shared exponent HDR (RGBE 9:9:9:5) texture format support OpenGL 2.0 support ATI Avivo? HD Video and Display Platform 2nd generation Unified Video Decoder (UVD 2) Enabling hardware decode acceleration of H.264, VC-1 and MPEG-2 Dual stream playback (or Picture-in-picture) Hardware MPEG-1, and DivX video decode acceleration Motion compensation and IDCT ATI Avivo Video Post Processor New enhanced DVD upconversion to HD new! New automatic and dynamic contrast adjustment new! Color space conversion Chroma subsampling format conversion Horizontal and vertical scaling Gamma correction Advanced vector adaptive per-pixel de-interlacing De-blocking and noise reduction filtering Detail enhancement Two independent display controllers Drive two displays simultaneously with independent resolutions, refresh rates, color controls and video overlays for each display Full 30-bit display processing Programmable piecewise linear gamma correction, color correction, and color space conversion Spatial/temporal dithering provides 30-bit color quality on 24-bit and 18-bit displays High quality pre- and post-scaling engines, with underscan support for all display outputs Content-adaptive de-flicker filtering for interlaced displays Fast, glitch-free mode switching Hardware cursor Two integrated DVI display outputs Primary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI) or 2560x1600 (dual-link DVI)3 Secondary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI only)3 Each includes a dual-link HDCP encoder with on-chip key storage for high resolution playback of protected content4 Two integrated 400MHz 30-bit RAMDACs Each supports analog displays connected by VGA at all resolutions up to 2048x15363 DisplayPort? output support Supports 24- and 30-bit displays at all resolutions up to 2560x1600 HDMI output support Supports all display resolutions up to 1920x10803 Integrated HD audio controller with up to 2 channel 48 kHz stereo or multi-channel (7.1) AC3 enabling a plug-and-play cable-less audio solution Integrated AMD Xilleon? HDTV encoder Provides high quality analog TV output (component/S-video/composite) Supports SDTV and HDTV resolutions Underscan and overscan compensation MPEG-2, MPEG-4, DivX, WMV9, VC-1, and H.264/AVC encoding and transcoding Seamless integration of pixel shaders with video in real time VGA mode support on all display outputs ATI PowerPlay? Advanced power management technology for optimal performance and power savings Performance-on-Demand Constantly monitors GPU activity, dynamically adjusting clocks and voltage based on user scenario Clock and memory speed throttling Voltage switching Dynamic clock gating Central thermal management ? on-chip sensor monitors GPU temperature and triggers thermal actions as required ATI CrossFireX? Multi-GPU Technology Scale up rendering performance and image quality with two GPUs Integrated compositing engine High performance dual channel bridge interconnect5  Our first impression of this card in the limited time we had is that it is amazing ATI put so much power into a single slot card. It does appear to run very hot, at around 155 degrees Fahrenheit by our initial tests but it is a single slot card and we can say the fastest single slot card on the market. A bigger heatsink/fan could have helped but it seems to be quite a powerful package for an amazing price.                   Here is our current test system.   Mother Board Asus M3A32-MVP Deluxe Wi-Fi, Asus Crosshair II Formula CPU AMD Phenom X4 9850 Black Edition Video Card Various Memory Corsair XMS Dominator 2GB Hard Drive Western Digital Raptor Case Tsunami Thermaltake Display Samsung 20" LCD Westinghouse W4207   Our test OS was Windows Vista Ultimate SP1 with Nvidia's 175.12 of Forceware drivers and ATI Catalyst 8.6. All the latest software revisions were used in our testing.     And we're off. The first thing we notice is that we do seem to be limited by our Phenom setup in the CPU hungry Crysis but also how amazing the 4850 is as a performer besting the 3870 by 7fps and meeting the 9800 GTX head on. Quite an achievement for the company written off by many not long ago.     Unreal Tournament 3 is the most popular graphics engine in use today and something we thus must test. Here we see two 4850s come out on top far and away besting two 9800 GTX SLI cards in every resolution and by 18fps at 2560x1600. The 4850 does it's best to keep up but comes in slightly under the GeForce 9800 GTX.   uake Wars is one of the last Open GL games on the market and may not have much of a life longer as an API for games but for now it's something we'll be testing. OpenGL has always favored Nvidia it does so here but ATI have made huge gains in the ability of their cards with the 4000 series.   Valve's Half-Life 2 proves to be much friendlier to the 4850 series and we again see some great performance from ATI.       Here the 4850 again comes in under a GeForce 9800 GTX but easily clobbers the previous ATI generation.         Pricing: CDW now has the Radeon HD 4870 here for $349.99. Newegg is selling the 4850 for $199.99.   As more etailers get on the band wagon we fully expect pricing to drop particularly with Nvidia announcing the GeForce 9800GTX+. Conclusion: While we haven't had a long time to look at ATI's new Radeon HD 4850 series of cards what we have looked at in gaming performance is nothing short of amazing for a $200 card and from a company treading water only a year ago. ATI is resurgent and the 4850 is just the what the company needed and AMD especially. AMD's CPU division could use some of the ability to compete that ATI has shown lately badly but for now ATI is the shining star from AMD with excellent integrated graphics and chipsets and now easily the best performance on the market from a single slot card. Nothing really comes too close and it is good to see competition heating up again from Nvidia and ATI that was dormant for too long. Now the question is does Nvidia have something up their sleeve soon, were they hiding something in that 18 month wait for a follow up to the GeForce 8800 GTX more than the very expensive GTX 280? We shall see but for now the Radeon 4850 does a good job of emulating a GeForce 9800 GTX at an amazing price and we can't wait to see what the 4870 is able to offer up. Congrats to ATI, now we just wish we had more time for a review in the future :). Score: 99%     '); //-->

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