Originally Posted by
HKPolice
9800GTX will not be a 'new' chip. It will still be a G92 but this time FULLY unlocked, probably with 144 or 160 shaders and 24 ROPs (384bit ram) + even higher default clocks.
G80 has 690Million transistors (including the 9 million in the NVIO chip)
G92 has 754Million transistors but the current 8800GTS only has 16 ROPs compared to 24 on the G80.
This makes no sense, why would NV make a chip that is basically identical to the G80 design with 64 Million extra transistors but 8 less ROPs??
Sure, the G92 has double the TMUs of G80, but if you look at the 7800GTX vs 7900GTX; they have identical chip functionality but 7800GTX is 302 million transistors vs 278 million in the 7900GTX!! Nvidia was able to shave 24 million transistors off the 7800GTX while keeping all the features. I have no doubt that they were able to pull off a similar trick with the G80 vs G92 since they had about a year to work on the design.
Obviously, there are still some parts of the G92 chip that are still hard locked. This would also explain why there are such delays with supplying G92 chips for the 8800GT and 8800GTS because each chip is being binned so thoroughly. It also makes more sense this way because designing a new chip specifically for the 9800GTX line would be too costly especially since it's one of the ultra high end cards and volumes will be very low.
Nvidia is very smart taking this approach because it gives the highest yields possible. With the RV670 chip, if only 319 of the 320 shaders are working, then the whole chip is useless and scrapped. With the G92 chip, if all the shaders work, they bin it as a 9800GTX, if only 129 of them work: 8800GTS, if 113 of them work: 8800GT and if only 97 of them work: 8800GS! Very few wasted chips.