XFX GeForce 7900GS PV-T71P-UDE3 Video Card Review :: XFX GF7900GS 480M 256MB Dual DVI TV XT Features

09-07-2006 · Category: Hardware - Video Cards

By Benjamin Sun
  • 90 nanometer low-k dialectic process
  • 278 million transistors
  • 20 Pixel Pipelines
  • 7 Vertex Shader Pipelines
  • 16 ROPs
  • 480MHz Core Clock speed
  • 660MHz Memory speed (1.32GHz effective)
  • 256-bit memory bus
  • DirectX 9.0c
  • Pixel Shader 3.0
  • Vertex Shader 3.0
  • HDR
  • Up to 4x Rotated Grid MSAA
  • 8x AA (mixture of MSAA+SSAA)
  • Up to 16x AF
  • 882 Million Vertices a second
  • Fill rate 9 Gigapixels a second
  • Transparency Anti-Aliasing
  • PureVideo HD

The 7900GS is based upon NVIDIA's G71 chip. The G71 is based upon TSMC's 90 nanometer process with 278 million transistors. NVIDIA's G7x series are smaller in die size than the competition due to fewer transistors. This allows NVIDIA to offer higher operating speeds with a smaller cooling system than the competition. That's one of the issues I have with cards like the 7900GTX and the X1950XT, their cooling requires two slots.

The 7900GS has 20 Pixel Pipelines, 16 Raster Pipelines and 7 Vertex Shader pipelines. This is similar in configuration to the 7800GT card that was released in 2005. In fact you could call the 7900GS in many respects a 7800GT on a 90 nanometer process. Take Note: the 7900GT has the same number of pixel pipelines and vertex Shader pipelines as the 7900GTX and 7950 GX2.

Pixel Shaders are used in virtually every computer and console game released today. Oblivion, for instance, offers Pixel Shaders throughout the game in the water, the clothing and armor the characters in the game wear, the textures in the walls and floor and more. Vertex Shaders in the game are used in the grass, in the facial animation of the characters in the game, in the movement of the characters and throughout. This game is an excellent example of what can be accomplished with Shaders.

HDR stands for High Dynamic Range lighting. The effect of HDR is to show natural lighting by highlighting the differences between the brightest light and the darkest dark. If you've ever gone outside and looked at the sky you can see where HDR is useful, as the sky can have a nearly infinite contrast when looking at an effect like the Aurora Borealis. Oblivion uses HDR in almost every lighted area. The shiny armor, the bright walls, the sky all use HDR. Without HDR the screen is a bit dull, with HDR enabled the game looks beautiful.

Anti-Aliasing is the reduction of jagged lines and angles in an image. The 7xxx series has several modes of AA including 2x Rotated Grid Multi-Sample AA, 4x RGMSAA, 6XS (a mixture of 2x MSAA+2x Super-Sample AA), 8XS (4x MSAA+2x SSAA) and more. The 7800 series introduced Transparency Anti-Aliasing to commercially available video cards. Transparent textures are not anti-aliased with MSAA. TAA applies either MSAA or SSAA to those textures allowing things like the interior of fences to be anti-aliased.

XFX GeForce 7900GS PV-T71P-UDE3 Video Card Review SLI connector

SLI connector

SLI stands for Scalable Link Interface and was introduced in 2004 along with the nForce4 SLI motherboard chipset by NVIDIA. Today, SLI is the number one multiple graphics solution in the market with many more NVIDIA SLI motherboards sold than the competing Crossfire solutions. To get SLI to work you need two of the same card, i.e. two 7900GSs, a SLI bridge, and a SLI motherboard. Once the cards are inserted in the motherboard, and the bridge attached, simply install the latest Forceware drivers, enable SLI with a check box or NVIDIA's new Control Panel and SLI is enabled.