It all depends on what you're using the computer for... Say you gaming on 1080p 1 monitor you should run 2 970 for overpower gaming pc or you can run a surround gaming setup @ 5750x 1080 or something like that. forgot. 2 980 will bottleneck monitors @ 1 monitor 1080p res. 2 980 is preferably for 1440p- 4k