Low gpu usage

[s26rech]

I have a 980ti sli configuration and it always worked fine. 1/2 months ago almost any game started heavy stuttering due to low gpus usage, in fact the cards always run low usage but never 99% ( 60/70/80/50 etc ), this is very annoying and it also happens in easy games ( rocket league doesn't go above 200 fps and it keeps stuttering ) and even using a single gpu in any of the pcie slots. I already tried to check temps, install differents drivers, overclocking cpu and ram, kboost, pcie power management, formatting to a fresh os, memtest and checking cpu and ram usage. I think it could be due to a bios/os setting because I already tried everything hardware and driver side but it could be wrong of course.
Any help?

i7 6700k ( stock due to high temps but even clocking it to 4.6ghz makes no effect )
Z170 Pro Gaming
Corsair H100i
Evga P1000
WD Black
Samsung 850 Pro Evo
2x4gb Kingston Savage 2133mhz
Sli 980ti g1 gaming
Haf X
W10 ( last build )

[jools]

have you tried disabling sli and running one gfx card

[jools]

at a time to see if its individual card or sli related

[s26rech]

2 minutes ago, jools said:

at a time to see if its individual card or sli related

Tried any gpu in any slot with no results, that's why I think it could be a bios/windows setting ( even if I formatted several times ) or something like a motherboard button

[cadd]

5 minutes ago, s26rech said:

Tried any gpu in any slot with no results, that's why I think it could be a bios/windows setting ( even if I formatted several times ) or something like a motherboard button

I had something odd like this except with 1 550ti, for some reason i couldnt boot with any usb pluged in or my gpu usage would be super low, after i booted i could plug anything in and the problem magically fixed itself after i a day or 2

[s26rech]

5 minutes ago, cadd said:

I had something odd like this except with 1 550ti, for some reason i couldnt boot with any usb pluged in or my gpu usage would be super low, after i booted i could plug anything in and the problem magically fixed itself after i a day or 2

So should I try to unplug any usb and then plug them after I booted?

[cadd]

Just now, s26rech said:

So should I try to unplug any usb and then plug them after I booted?

yea thats what i did.

[s26rech]

Just now, cadd said:

yea thats what i did.

I'll surely try this out

[s26rech]

12 minutes ago, cadd said:

yea thats what i did.

Just tried, stll nothing 

[s26rech]

Bump, I noticed that gpuz is saying "PerfCap Reason: SLI" could this be the issue?

[s26rech]

And playing with a single gpu I get Reason: VRel

[s26rech]

Bump

[s26rech]

Unigine Heaven usage:

[s26rech]

Gonna keep bumping

[s26rech]

bump

[SmashinMachine]

what about to set to oerformance mode in nvidia control panel?