Stock clock GTX480 3-way SLI (197.41) vs stock clock HD7950 CF (12.1)(with i7 965 at 3.8GHz @ 1920x1200)
Far Cry 2 174 vs 172 (major CPU bottleneck)
Anon 1404 118 vs 123 (major CPU bottleneck)
Metro 2033 76 vs 80
Battlefield BC2 104 vs 125 (major CPU bottleneck)
1.HD7950 CF wins. This means, HD7970 CF wins more.
2.At 1920x1200, CPU bottleneck happens very often.
1. HD7970 CF is preferred as the pair is stronger than GTX480 3-way SLI
2. Your current mobo Asrock Extreme4 Gen3 does not support 3-way SLI natively because its third PCIEx16 slot only gives x4 speed. Therefore, it does not have Nvidia's certification. Even if you get the 3-way SLI to work, the x4 slot will slow down the other 2 cards. So, this is not recommended.
3. I am not too sure about the relative performance of 2500k at 5GHz vs i7 965 at 3.8GHz, I still feel uncomfortable of matching the powerful HD7970 CF with your current 1920x1080.
4. You may consider:
a. Keep the GTX480 SLI and upgrade the monitor to 27'' (1920x1080)--least expensive. This upgrade is more an visual experience upgrade as the size of monitor increases noticeably from 22'' to 27''
b. Same as above but upgrade to a single 27'' (2560x1440)--more expensive
c. Upgrade to air-cooled HD7950 CF and a single 27'' (2560x1440)-- HD7950 has a higher C/P ratio than HD7970, IMHO. Additionally, wait a couple weeks as GK104 cards is coming out soon and I strongly think the arrival will make price of HD7950/7970 to drop.
Edited by windfire - 3/13/12 at 7:48am