700+ Mtexels!

Fill rates

Having onboard T&L is great, but the real motor behind the Savage2000's speed is the 700+ Mtexels/s fill rate. Why does S3 say 700+ Mtexels? Well, the clock speed of the core and memory determine the fill rate.

S3's 700Mtexel/s number is actually very conservative. They're only clocking the chip at 175MHz to achieve the 700 number. You multiply the clock speed by two for the dual pixel pipeline to get the number of pixels per second, 350MPIX/s (175MHz x 2 pixels). Then you multiply the MPIX/s number by two for the dual texturing applied to each pixel to get the final 700Mtexels/s (350MPIX/s x 2 textures).

S3 states that the Savage2000's core and memory can go up to 200MHz. If we use the 200MHz clock speed, we come up with an 800Mtexels/s (200 x 2 pixels x 2 textures) fill rate. Of course, the Savage2000's fill rate can be even higher depending on how far you can overclock the card.

What are the fill rates for current cards?

Let's compare the Savage2000's fill rate to the Voodoo 3 3500's 183MHz clock, and the Xentor Ultra TNT2's 175MHz clock. Both the Voodoo 3 and TNT2 can only do one multi-textured pixel per clock. That means the Voodoo 3 only has a 366Mtexels/s (183MHz x 1 pixel x 2 textures) fill rate and the Xentor only has a 350Mtexels/s (175MHz x 2 pixels x 1 texture) fill rate.

800Mtexels/s?!?! Isn't that the original Glaze3D?

Yes, that's right. The original specs for the Bitboys Glaze3D processor called for a dual pixel/dual texture pipeline with a 200MHz clock for the exact same 400MPIX/s and 800Mtexels/s fill rates as the Savage2000.

The original Glaze3d chip missed the targeted Q2 1999 release date, and Bitboys announced a new Glaze3D design claiming 1200Mtexels/s and 2400Mtexels/s fill rates just last month. We don't expect to see Glaze3D cards until the first half of next year, but it looks like S3 is coming through with the original Glaze3d right now, and it's called the Savage2000.

Not all the Savage2000 cards will run at 200MHz. Like 3dfx and Nvidia, S3 will release the Savage2000 at different clock and memory speeds to target different market segments.