i5 4690k / i7 4790k PPD

[Teddy300]

Hello,
i decided its time for a new cpu but i would like to know the PPD of the following cpus:
- i5 4690k
- i7 4790k
- xeon 1231 v3 (unlikely but maybe)

Would you recommend buying one of this cpus used on ebay or new? I normally avoid ebay for electronic items but cpus last usually very long, so i feel a bit more save?

Thank you very much for the help

[foldy]

i7 4790K has the highest clock 4Ghz so is the fastest CPU.
But if you look for highest PPD you should fold on a GPU,
e.g. a Nvidia Gtx 970 has the same price like the i7 4790K but 15 times PPD

[DemonfangArun]

seconding the above: get whatever CPU you like, and stuff box with as many GPUs as the motherboard and PSU can handle is generally the way to go.

[Teddy300]

Ok think i will go with the i5 4690k. Iam already folding with my gtx 960 and my little dual core.