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Review: NVIDIA's GeForce 6800 Ultra GPU

by Ryszard Sommefeldt on 14 April 2004, 00:00

Tags: NVIDIA (NASDAQ:NVDA)

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ShaderMark 2.0

Shader Precision

ShaderMark 2.0 highlights GeForce 6's changed default data precision in shaders. iXBT's PixelShader 2.0 precision test shows us the default precision for PS2.0 in DirectX 9.0.

NV40 R360
Default PS2.0 precision s23e8 s16e7

As you can see, R360's important pixel shader precision format is FP24 (s16e7). NV40 is 32-bit throughout.

On to the ShaderMark 2.0 results.

ShaderMark 2.0 Results

ShaderMark 2.0 is run in Anti-Detect mode using PS2.0 and no partial precision hinting.

ShaderMark 2.0 performance

When NV40 can complete the test (more on that shortly) it's anywhere from 2x to 4x quicker. The impressive looking result is for the Per Pixel Environment Mapping test. Raw shader throughput looks quite impressive, according to ShaderMark 2.0 at least.

ShaderMark 2.0 notes

ShaderMark 2.0, on NV40, starts up with a warning that NV40 can't run all shader due to lack of a required 16-bit floating point format. While that's true (it doesn't expose D3DFMT_R16F), it does expose other 16-bit FP formats that ShaderMark 2.0 could use to complete the tests (like A16B16G16R16F, a 64-bit format with 16-bit per pixel components). An update to ShaderMark should fix things.