XFX AMD HD RADEON 6850 Review

Fri, 2010-10-22 01:06 -- Benjamin Sun

 

            1.7 Billion Transistors

            960 Stream Processors

            255mm2

            12 SIMD Engines

            48 Texture units

            128 Z/Stencil ROPs

            32 Color ROPs

            Max Board Power 151W

            Idle Power 19W

            1GB GDDR5

            Single 6-pin power

            2x DVI, 1 DisplayPort, HDMI

            775MHz Core Clock speed

            1GB/second memory clock speed

            128GB/second memory bandwidth

            Updated Tessellation unit

            1.75 TeraFLOPS computing power

            24.8 Gigapixels/second pixel fill rate

            37.2Gigatexels. /second texture rate

            Dual Rasterizer

            256-bit GDDR5 memory interface

            Morphological Anti-Aliasing

            UVD3

            APPP

            Blu-ray 3D

            Eyefinity

            HDMI 1.4a

            DisplayPort 1.2

 

The new AMD HD 6850 is based upon their Northern Islands architecture, with a chip codenamed Barts Pro.  The Barts chip starts off with AMD’s familiar 16 SP SIMD, which is capable of four operations, a clock plus a Multiply ADD operation, a clock for five processors per SP. So each SIMD unit has 80 Stream Processors. There are two configurations launching today, the HD 6870 and the HD 6850.

The HD 6870 has 14 SIMDs with 80 SPs each for a total of 1120 Stream Processors. The HD 6850 has two less SIMDs with 12 each having 80 SPs for a total of 960 SPs.  The card has 48 texture units, 32 ROPs and 128 Z/Stencil ROPs.  AMD says that their HD 6850 card can do 1.75 TeraFLOPS/second of computing power compared to the 2 TeraFLOPS a second on the HD 6870. The fill rate of the card is 24 Gigapixels/second.

The HD 6870 has a memory speed of 4.2GHz compared to the 4.0GHz clock speed on the HD 6850 using a 256-bit memory bus. The HD 6870 has a memory bandwidth of 134.4GB/second while the HD 6850 has a memory bandwidth of 128GB/second. Now mind you this card is targeted at the sweet spot of the gaming market in between $200-300 with the HD 68xx series. This should offer near the same performance of the 5850 for a lower price point on a smaller die.

One improvement AMD has made with their HD 6 series is the improved Tessellation performance. The HD 6870 and 6850 has up to 2x the performance in Tessellation over the HD 5870 series in differing situations. This means improved performance in DirectX 11 games over the previous generation as games like HAWX2 which uses a lot of tessellation throughout the game and Aliens Versus Predator, which uses tessellation throughout, will benefit from increased performance in this regard.

3D is really taking off with the release of 3D Televisions, and Blu-ray 3D. NVIDIA introduced 3D Vision last year to their graphics cards to support 3D gaming on while using stereoscopic glasses and a 120Hz monitor.  AMD introduced support for their version of 3D with the HD 5 series but hasn’t gotten much traction. With the launch of the HD 6 series AMD is moving towards bringing support for Blu-ray 3D support and stereoscopic 3D support for games with over 35 DisplayPort products, 45 validated and ready titles with hundreds of compatible games and affordable Single-Link DP to DVI adapters to allow for stereoscopic 3D on a budget.

Anti-aliasing improves the image quality of a game by removing the jaggies and image artifacts from a game or application. Current methods of anti-aliasing include super sample anti-aliasing, which ups the internal resolution by the number of samples, and down samples the resulting image. Multi-Sample anti-aliasing each pixel at the edge of a polygon is sampled multiple times. For each sample pass a slight offset is applied to all screen coordinates. By averaging all of these samples the result is a smoother transition of the colors at the edges.  The number of samples taken for each pixel indicates the level of multisampling, so 4x is 4 samples from each pixel at the edge of a polygon. AMD is introducing a new feature with the HD 6 series called Morphological Anti-aliasing. MLAA adds a post-processing pass on the fully rendered image and anti-alias the sharp edges using DirectCompute. All AMD DirectX 11 cards support this new technique from the HD 5450 to the HD 6990 inclusive once the driver is released at a later date.

AMD Makes a solid entry into the mid level video card market as the new XFX HD RADEON 6850 hits the shelf!

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