Notes

Texture read performance is 190MP/s¹ for RivaTNT and 250MP/s for PERMEDIA3 (2 texels per clock). But unlike PERMEDIA3, RivaTNT (as well as Rage128) can process 2 pixels per clock, e.g. with bilinear filtering its fillrate is 190MP/s¹, while PERMEDIA3 has it at 125MP/s.

Theoretical fillrate of TNT is 250Mpps. The matter is that nVidia has planned to set internal GPU clock rate to 125MHz, but is currently producing 95MHz 0.35-micron chips 95Mhz¹. The 250Mpps products are due next year, so nVidia will be producing 125MHz TNT2 using the 0.25-micron technology. At the moment fillrate and triangle setup engine of RivaTNT is 190Mpps¹ 6 million¹ triangle/s, respectively.

With advanced 3D features enabled the fillrate is:

The NEC PowerVRS2 supports both bump map embossing and dot product bump map. There are many rumours that PowerVRS2 supports multitexturing (similar to Permedia3).

Without multitexturing (e.g. with bilinear filtering) RivaTNT performs twice as fast as - at 190MP/s¹, while the performance of PERMEDIA3 remains the same - 125MP/s.

At the moment we believe there will be two types of graphics chipsets:

• Able to process 2 pixels per clock (e.g. RivaTNT, Rage128 and RRedline) and performing twice as fast in this mode.
• Not able to process 2 pixels per clock (e.g. PERMEDIA 3).

This is not critical at the moment, since most games will in the near future use either multitexturing, or trilinear filtering (not just bilinear), but performance will be equal in such situations. But when more powerful chips arrive (e.g. Glaze 3D) this will become important, since quality of games will grow to 2 textures per clock and 8 textures per clock.

The fillrate of Rage128 is 200MP/s². The texture read speed is 1 GT/s (gigatexel per second). Simple calculations indicate that the read speed is 800 MT/s and another 200MT/s are gained by caching. As you remember, Rage128 features pixel and texture caches.

Little is known about Rendition RRedline. We just know that its fillrate will be 250MP/s.

¹ - This relates to RivaTNT 95MHz. The ready products operate at 90MHz, higher clock rate being a matter of overclocking at your own risk.

² - The first revisions of ATI chip will work at 100MHz. After October 1998 ATI is going to boost clock rate to 125MHz.

³ - i740 supports software DVD decoding only at 720x480.

⁴ - Savage3D supports software DVD decoding in all resolutions starting with 800x600 as well as at 720x480 (MPEG2 original resolution).

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