Good evening guys and gals,

I've been having alot of trouble recently with my pc setup the specs are as follows;

I5 4690k @ stock
Evga 980ti with backplate @ stock
Asus z97-Ar mobo
8gb corsair vengeance lp ram
Evga 850w P2 psu
Windows 10 64bit enterprise.

Now I recently sent my GPU back for an RMA as it wasn't working properly lots of artifacts low clock mem speeds etc so upon receiving my new one I'm still having the same kind if problems.

Gpu usage in unigine heaven benchmark is 95-100% mem is 3506mhz gpu clock is 1316mhz but my Tdp is 40-50% meaning I'm getting next to no performance at all!
15-30 fps when realistically I should be maxing out close to 100fps+
This is all at 1080p.

It's the same with playing games. fallout 4, mgsV, witcher 2/3.

Now I've obviously I've changed the GPU, all the drivers are up to date.
Tried reseating countless times, unplugged and re plugged all cables.

Have yet tried my old gigabyte z97 mobo to see if it's the motherboard, but now I'm starting to think it's my psu?!

I need some serious help as I'm at the end of all the stuff I know!

Many thanks Kieron.