Originally Posted by 3870x2
You are trying to tell me a P4 with a 680 will not perform any better than a P4 with a 660?
I think you are focusing on the wrong part of what I said. I am not saying the P4 is relevant, forget about the P4 altogether. I am saying that there is no bottleneck, only scaling with a processor. The faster the processor the better of course.
Yes, I'm telling you, that at a certain point you will see no performance boost going from a 670 to a 680 if the CPU is holding you back that much.
The 680 might allow you to run a higher resolution, or turn on some more eye candy, but if you leave the settings the same, at some point the CPU will become the limiting factor and increasing the GPU power will not give any performance gains.
Now most modern games are GPU bound on any reasonable settings, so the CPU makes little difference as long as you have a modern CPU, but there are definitely some games out there still that rely heavily on the CPU. If the CPU can only do enough calculations to run the game at 20FPS, then the game is going to run at 20FPS, it doesn't matter if you have a 650 or dual-680s, the game will still run at 20FPS.
Any point where the GPU has to wait on the CPU is a bottleneck, and yes it does happen.