I'm thinking about getting some more graphics power. 470 SLI got my attraction. I know my CPU will bottleneck them, but how bad? It's a Q9650~4GHz. I play at resolution 1920x1080p. I intend to overclock them but if my CPU proves to be a too large bottleneck I won't. Any ideas?
I seriously doubt a Core 2 at 4GHz is going to bottleneck any standard GPU using game at this point. Someone in another thread was talking about quad cores being a bottleneck right now, that's nonsense considering almost all programs out there use only 4 threads or less. Those of us who OC to the maximum do so only because we're crazy or have CPU dependent programs. Well, let me put it this way, any slowdown caused by your CPU will not be noticeable considering any game which two 470s + a C2D @ 4GHz can't pull off 60fps in would be something that's severely GPU limited.
Okay When I bought my GTX 295 I read some threads about it. Everyone said the C2Q should run at 3.6GHz otherwise it would bottleneck the 295. So I figured 470 SLI would require an even more powerfull CPU.
Think of it this way, the ideal scenario is that your CPU reaches a speed that it does all the CPU dependent calculations for the game and all running processes. That way the only thing left that could slow you down are the calculations done by the GPU and therefore you can only be GPU limited. So for example if you need 3.6GHz to do all the CPU calculations, anything beyond that won't give you improved performance since all the calculations you need done by it were already within the CPU's ability. A 4GHz C2Q is almost always enough. In my previous post I had a typo, I wrote C2D, I meant C2Q. Games these days use 4 threads and can actually pressure all 4.