Originally Posted by Ninja Prime
To clarify this, they are judging against Tesla supercomputing boards. The first fermi computing board has a DP flops rating of 515 DP flops and a TDP of 238 watts. This amounts to 2.16 DP flops per watt. To hit their claimed 2.5 times this, they would hit 5.42 DP flops per watt. So, 5.42 x 238 watts = 1.28 teraflops DP, and since NVs DP rate is half their SP rate, SP flops would be 2.56 teraflops SP. Doesn't even beat the 6970(2.7teraflops), let alone the 7970(3.79 teraflops), at similar power.
It also depends on what TDP they are targeting for this 2.5x number. As lower end tends to be more efficent, maybe this 2.5x number only applies to a 200 watt product, that still puts them at 1.08 teraflops DP, still in line with the rumored "over 1 teraflop DP" number. I suspect this might be the case, and their high end will be a dual GPU board product.
My main point though is that AMD achieves this with dual precision precision maximum(1 terraflop) with a GPU using "only" 4.3 billion transistors, though it does run at fairly high clocks, and can overclock another 200mhz....I'm focusing on the dual precision figure since it's the one used in mission critical and scientific computing environments where the results have to be as precise as possible, and i do keep in mind these are theoretical maximum figures and not likely to be acheivable in practical terms.
Now on Nvidia's side and with the current fermi, it does a little over half as much in dual floating point and already uses 3+ billion transistors, so for AMD to do be pretty much twice as fast in that dept with "only" an extra billion transistors, and still be 50% faster than their previous high end HD6970 in gaming is quite an achievement to say the least, and both Cayman and Tahiti are only running with a 75Mhz difference in clock speeds(850 vs 925Mhz)....Like it or not. it's one efficient chip and makes every transistor spent on it's design count for something, while keeping the overall die size as small as possible.