P: Restarts when trying to use Object Selection Tool with hyper threading enabled

Ok. In this case, I think we could say that this is not caused by HW. 🙂

Tried it, doesn't work. PC restart with every different cache level (tried from 2 to 6)

No, it's not. 
My power source is a Gigabyte 750W.
Also I ran a multitude of benchmarks, Mem86 test for 24 hours, etc, and there aren't any errors in any other software other than Photoshop (I use 3DS Max, render stuff, etc).

Please include the version of Ps you're using and which OS version. I think the object select uses the GPU, so include that info too.
Also link to other threads with users having the same crash.

Hi, Razvan Matei

Edit Men Click 
Preferences>Performance>Prefernces windows
Cache Levels : 4 up to 6-7

OK. Click

Could it be a hardware problem? What is your power source? Because if CPU + GPU goes 100% and power source is not strong enough it could outage your PC. i9 is power hungry CPU.