GPU Usage drops to 0%

[Baner]

Every 1 minute GPU, BUS and FB Usage drops to 0%. Voltage is stable.(IMAGE INCLUDED). It appears for 1 sec and after that it's working fine for ~1 min.

Played Outlast 2 everything was fine. Games with less requirements as cs go are working properly. FPS drops in Hitman, Sniper Ghost warrior 3, Mass Effect Andromeda.

ITS NOT TEMP ISSUE. PC is stable (benchmarking for over 30 mins). Drivers up to date.

 

Specs : (DxDiag INCLUDED)

GTX 760 by evega

Intel 2600k

RAM 8 GB 1333

PSU 620w

Asustek p8z68-v vx

 

What I tried:

Underclocking, undervolatege/overvoltage, forcing fan to 100%
Update/reinstall drivers/chipsets

Opening case (PCI slot, cables, dust etc. check)

BIOS (update,fixed voltage (tried auto also), C1E is disabled, turbomode disabled)

Diagnostics - mdsched (ram),sfc/scannow, dxdiag, viruses

Closing all background applications

 

Click on image below and then press "Copy image address" there you can see things.

 

DxDiag.txt

[stefanDB]

is the rest of the system okay? is the CPU stable and cool? (I don't really know what this is but I am just suggesting things)

[Baner]

CPU core's temps are ok, it drops a little with gpu, but I think it happens because cpu stops feeding gpu (because its gpu usage 0%) and it leads to cpu usage drop.

[Baner]

 Any solutions despite "buy new pc/psu/internet provider" ?