Upgrade to i5 or i7?

[CurseTheSky]

You guys are underestimating i5/i7 speed. First of all,they are not just 30 % faster. They are about 50% to 100 % faster then core 2 quad at same Ghz.
I mean all the info is on the internet,you just have to find the right benchmarks.I can link some if you guys want.
It all comes down to where do you expect to see the speed difference.
For example,in gaming if we take op's rig,he is not going to see even 30 % speedup in games,not to mention 100 %
Why ? Because his gpu will severely bottleneck an i7. However,if he do what he says and actually buy another 280 to put it in sli,situation will change.He will see 30 to 50 % faster fps in games with 2 280's and i5/i7 then with his current cpu.
If he add another 280,his games will run double the speed they would on his current cpu
Bottom line,i5/i7 are faster,and yes they are much faster per clock then core 2 quad
Problem is,you can't see that speed if another part of your rig is going to bottleneck the cpu

Yes, please post these benchmarks. Other than a few reviews stating that X58 / i7 kicks the crap out of the competition for extreme enthusiast multi-GPU setups, I haven't seen anything of this sort.

Furthermore, no matter how much you believe it, Bloomfield and Lynnfield are not much faster than Core 2 Quad clock-for-clock, especially not 50-100% faster (please post a benchmark of equally clocked C2Q and i7's with HT / turbo disabled doing some rendering or encoding... is the i7 double the speed?). Check out the links Qbah posted - maybe a 5-10% increase? You also have to take into account the other slight performance upgrades that come from the entire platform switch - integrated memory controller, DDR3 memory, turbo mode, etc. Taking those into account, I'd say the processors are nearly equal clock-for-clock.