Gigabyte GV-NX78X256V-B 7800GTX Video Card Review :: Features

• Pixel Shader 3.0
• Vertex Shader 3.0
• 24 Pixel Shader pipelines
• 8 Vertex Shader pipelines
• 430MHz core clock
• 302 million transistors
• .11 micron process
• Transparency AntiAliasing Multisample and SuperSample
• Gamma Correct AntiAliasing
• SLI

NVIDIA chose to use the .11 micron process for their G70 chip. With a transistor count exceeding 302 million, the GEFORCE 7800 Ultra is a huge chip. NVIDIA has implemented power saving techniques learned from their mobile parts into the 7800GTX, meaning even though the 7800GTX has more than 80 million transistors than the 6800 Ultra and has a higher clock speed than the 6800 Ultra the card actually draws less power than its predecessor.

Clock speed on the 7800GTX from GIGABYTE is 430MHz, the same as NVIDIA's reference card. Several manufacturers have released cards with a 450MHz, 470MHz or even 490MHz default clock speed. My preference is to have a factory overclocked card fully under warranty, as it offers better performance for the same price as the competition. Hopefully, GIGABYTE will release another version of this card with a factory overclock.

G70 has 24 Pixel Pipelines a 50% increase over the NV4x who had 16 Pixel Pipelines. The output of the card is still 16 Pixels in a clock, the same as the NV4x series. With a pixel fill rate of 7.32 Gigapixels a second, the 7800GTX will have little problems with fill rate situations in today's games. The texel fill rate of the 7800GTX is 10.3 Gigatexels a second.

The key features of the 7800GTX card include support for Pixel Shader 3.0 and Vertex Shader 3.0. These are the key components of Microsoft's DirectX 9.0 API (Application Programming Interface). Pixel Shaders allow small programs to be performed on pixels and provide special effects like realistic looking water, realistic looking armor, realistic translucent skin with blood vessels and realistic looking lighting.

Vertex Shaders allow for effects like displacement mapping, geometry instancing, and the 7800GTX supports infinite length vertex shader programs. The 7800GTX has 8 Vertex Shaders, a 25% increase over the previous generation 6800Ultra cards. The 7800GTX can output two vertices per clock cycle, giving a maximum theoretical geometry performance of 860 million vertices in a second.

The human eye is an amazing device. It's been said that there are 10 to the 12th power range of light intensity variations. The human eye can only differentiate between 1000 to 1 range of variation. Before HDR (High Dynamic Range) came along in video cards, the range of light intensity in video cards was 256 to 1. The GEFORCE 6800 Ultra was the first NVIDIA video card to support HDR rendering. This allowed for a intensity range of 65,536 to 1 allowing for increased realism when a bright light such as sunlight is reflected in the environment.

NVIDIA has finally offered anti-aliasing improvements with their 7800GTX video cards. Gamma Correct AA was first introduced in gaming video cards with the RADEON 9700 Pro from ATI. Often color on a monitor is "drained out" due to incorrect gamma settings due to the way computer monitors work. With GCAA enabled the color is more realistic and brighter. Transparent textures abound in computer games today. Often, a transparent texture is used to represent a fence or vegetation in a game. With regular multisample AA, the interior of these textures are not antialiased, making a mess of the look of the fence or vegetation. TSSAA and TMSAA help to alleviate the problem.

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