Sandy Bridge, Haswell, or Skylake

[prozart]

Alright so I've tried finding an answer online but it seems like most people are asking if it's worth it to upgrade from one processor to another and the consensus seems to be that the mild boost in performance isn't typically worth it. I will be building a new PC however and would like opinions on what is the best bang for buck going used on eBay. Thus far I've only purchased the tower, the power supply, and two EVGA 970 SSCs, I'll be buying the motherboard and RAM once I decide on a processor. The computer will mainly be used for gaming and I'm hoping to be able to play at 4k on less demanding games like CS:GO. Any help or advice would be appreciated. Here are the approximate prices I've found on eBay.


6600k $240
4690k $215
4670k $200
2500k $140

If you could also recommend a decent SLI motherboard with the processor recommendation that's be awesome. Thanks for your help!

 

[Onefurrybanana]

I wouldn't consider anything sandybridge. The difference between haswell and skylake is a few frames but supports more ddr4 ram and is of course newer. Out of all of those i would go with the 6600k. I personally use a titan x with a 5960x for my 4k and it runs well.