question about EFB vs AA

[sixor]

hi, i just wish to know which one is better 3x efb or 4x AA

i tried to enable both but there are slowndowns, maybe i could Oc my gtx460 later at 820-1130

what do you think is the best quality-performance for this gpu?

currently 6880, 1440x900, efb3x, nvidia gtx 460 oc

thanks