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View Full Version : Can the 6800 U do 64 shader operations in one pass under the right conditions?


pat777
05-04-04, 03:18 AM
I think 64 shader operations with the GeForce 6800 Ultra is possible.
If a pass has no color value GeForce 6800 acts like 32 pixel pipelines.
If a pass has no textures then ONE 6800 pipeline can do 2 shader operations.
2*32 is 64. Can the NV40 really do 64 shader operations in one pass?

MontoyaSG
05-04-04, 03:46 AM
i thought on their launch it's 128 shader ops per cycle

pat777
05-04-04, 03:48 AM
i thought on their launch it's 128 shader ops per cycle
That sounds extremely impressive even in only certain situations. Perhaps I'm forgetting about the multiple operations per shader unit.

Demirug
05-04-04, 05:50 AM
Do not confuse operations and instructions here.

nVidia counts a little bit different for the NV40. A operation is only a scalar calculation. A instruction consist of upto four operations. You can execute upto 8 operations and 4 instructions per clock and pixel.

The next propblem here is that a NV40-instruction is not equal with a DirectX PS instruction. In some cases you need more than one NV40-instruction for a DX PS instruction but on the other hand there are NV40 instructions that bind together more than on DX PS-instruction.