Originally Posted by zmatt
GDDR5 is more than twice the speed of GDDR3 so to beat it the 275 would need more than double the bus length. It doesn't.
Really the GTX275 is Nvidia trying to steal ATI's fire form the launch of their card. Its a reaction card and really adds nothing to their line. The current GTX cards cover every aspect of that market segment. Instead of playing tricks they should work on trying to beat ATI in a price war or something more productive. the 275 is simply a 280 with the 260's memory interface.
Except that ddr5 is NOT more than double the speed. The 4870 runns at roughly 4ghz, the 285 runs at 2500+. So therefore, the bus speed more than makes up for the speed of the ddr5.
Also, why does everyone hate Nvidia for being having better marketting than ATI. Ati has done every single "trick" that nvidia has done, just at different times. I guess its just trendy to hate on nvidia right now.
ATI 975mhz x4= 3900 x (256bit bus / 8) = 124800mb
Nvidia 1161mhz x2= 2322 x (448bit bus / 8) = 130032mb
Thats only 1.6x as fast. Also, when overclocking memory, you gain more bandwidth out of a wider bus than you do out of faster memory.