Originally Posted by
gOJDO
1) The clocks are not 20% higher. PCI-e, which is the interface connecting the two GPUs and the NB is clocked same. The core clock is clocked 17% higher.
2) You can count on one hand the games that in a very specific case(at certain scene when playing with everthing @max: resoultion, settings, AA and AF) can benefit from frame buffer larger than 1GB. There is no game yet that can utilze 2GB frame buffer at everything maxed out. I bet that in 95% of the games there would be no difference in perofrmance between the 4GB and the 2GB version of the card @same clocks.
3) Never compare single GPU scalling with multi GPU scalling. Just check the difference in performance between Asus MARS and regular GTX 295. MARS has more theoretical computing power compared to the regular GTX 295, but in reallity the difference was marginal.
4) I owned a systems with a 4870X2 on a Q9450@3.9GHz, and 2x4890, a GTX295, a 5870 and 2x5870 on an i7-920 @4.2GHz~4.4GHz. I did a lot of benchmarks and came to the conclusion that a dual-GPU performance never scales linear with frequencies, although the CPU bottleneck was basically avoided.
So, that 28% gain is a cherry picked result form a lot of benchmarks. And if that is the best, I guess the average will be at half of that at best.