An i5-2500K at 4.5GHz is mostly overkill for a 6990 above 1920x1080.Really? I thought I saw benchmarks to the contrary. Something like SB having double the FPS of Penryn. Perhaps that was at low res, I don't recall.
If that's true, then it's good to know. I built my BIL a computer a year or two ago, with a Q9550 @ 3.5, and a pair of HD6870 cards on an X48 mobo. Was wondering if I should consider upgrading his computer, or whether it will be good enough for future games for the next couple of years.
My personal opinion is that the rig is pretty damn powerful as-is, although slightly less powerful than an i5-2500K @ 4.4-4.5 and a 6990.
Any benches that you see run with a big disparity, *always* have the games benched at 1680x1050 (or below) with no AA and (mostly) medium details.
For gamers, there is no practical difference from running a Penryn Quad or Phenom II X-4 to a Sandy Bridge setup - as long as the CPUs are reasonably (overclocked) and the resolution and detail settings are maxed out; And i have tested this with GTX 580 SLI and HD 6990 Tri-Fire using my i7-920 from 2.6 to 3.6GHz compared with Phenom II and Penryn.