Ik kwam bij Voodoo Extreme deze erg handige post tegen waarin het verschil tussen Megatexels en Megapixels (altijd verwarrend) wordt uitgelegd. Check it:
Megatexels is how many millions of texels can be fed down to the card's pipeline per second (peak). Megapixels is how many millions of pixels can be put out to the frame buffer (peak).
Now, for as a point of comparison the Voodoo1 was 50 megatexels and 50 megapixels. The Voodoo2 was about 90 megapixels and 180 megatexels. This meant that if multitexture was on, you could send down two textures combined at 90 megapixels. If you had separated it into two single-texture passes, it would go as two 90 megapixel passes, or 45 megapixels total. Now, the TNT (which supports multitexture) had (I *think*) about 125 megapixels and 125 megatexels. The reason for this is because in single-texture mode, it would fetch two texels and write two pixels at the same time (peak). In multitexture mode, it would fetch both texels from both textures and write one pixel as a result. So that's why the numbers are equal.
So when S3 claims that they have a 700 megatexel framerate, it's *feasible* that per texture it's 175 million texels, so a peak fill rate of 175 megapixels. Or it could be that their megapixel number is somewhere higher than 175 but lower than 700 and they would rather just announce the higher megatexel number. I really doubt that they're hitting 700 megapixels, as that would have been more impressive for them to say and they didn't say that. It's probably more on the order of 350 megapixels or so.
Either way, barely anything currently uses 4 texture units, though Unreal and Quake 3 could probably make use of them. It is nice that they have four on there for future stuff though.
In conclusion, the megatexel number and megapixel numbers are two very different numbers, and should be posted next to each other to gauge the performance of one card against another.