D
580 would be a overkill at that resolution won't it?
Anyways 4ghz you say? The x4 managed to handle the 5970 without any worries
http://www.legionhardware.com/articles_pages/cpu_scaling_with_the_radeon_hd_5970,13.html
Are you talking about the stock Gtx 460? That's not a stock Gtx 460
5970 at max
http://www.legionhardware.com/images/review/CPU_Scaling_With_The_Radeon_HD_5970/Batman_02.png
http://www.legionhardware.com/images/review/CPU_Scaling_With_The_Radeon_HD_5970/Wolf_02.png
http://www.legionhardware.com/images/review/CPU_Scaling_With_The_Radeon_HD_5970/L4D2_02.png
http://www.legionhardware.com/images/review/CPU_Scaling_With_The_Radeon_HD_5970/COD_02.png
http://www.legionhardware.com/images/review/CPU_Scaling_With_The_Radeon_HD_5970/COH_02.png
you were saying