As of late, I've been basing all my judgements of how good a graphics card is by its memory bandwidth (i don't mean 1gb or 3gb, i mean amount of GB/S). Isn't this the right thing to do? It's worked well so far. E.G a 7970 has 260 odd GB/S bandwidth, and anything which performs worse, has a lower bandwidth. Another good example is the gtx 690, which has an insanely high bandwidth (higher than any other card right now) and it also performs better than any card. It seems to work well. The more GB/S the better, and a lot has proven this, but I would like to know if there is something which proves this in a more accurate way, because there are a few exceptions every now and then, like an old as hell GPU with 200GB/S getting crysis at like 40FPS, so it's not 100% accurate. Is there anything else which can be used?
You should never judge a gpu on bandwidth, memory speed, or clock rate. They are not comparable between architectures. It's really really easy. Look at benchmarks and reviews. That's what they are there for