Question 'm not sure why my GPU is under performing

[Mihemm]

I have a 1080ti and a 7700k with 16gb of ddr4 ram but in every game i play my frames are lower than they should be and in all the benchmarks i run my scores are lower than they should be, for example I'm only hitting a score of 14k in firestrike whereas 1080ti's should all get above 20k. I have tried all the nvidia control panel settings and reinstalled drivers twice and updated my bios but nothing seems to work.
Any help would be greatly appreicated.

 

[Deleted member 2731765]

Which Power Supply unit/model are you using to power up the GTX 1080 Ti ? List the exact PSU model number/brand. Is the GPU seated on the primary PCI-e x16 slot on your MOBO ? Have you tried changing the Windows Power Management settings as well ?

 

[Mihemm]

I've changed the windows power management settings, I have a 650w power supply but I'm not sure how to find the brand without picking apart my pc

 

[Mihemm]

The psu is this one
Corsair CP-9020098-UK VS Series ATX/EPS 80 PLUS Power Supply Unit, 650 W
I have a z270x ultra gaming motherboard and it is in the silver PCIe slots closest to the CPU