Ok, so we have ruled HW out beyond a reasonable doubt. Earlier in the topic you mentioned that you have tried both 2.80 as well as 2.81. It might be a bug in both 2.80 and one that still exists in 2.81 as well.
Might be time then to maybe make a bug report to the tracker.
Do note that the 580 and 590 are both basically the same architecture(lithography difference tho) and the potential bug might be affecting them specifically.
Thank you very much for the information bro, but can you tell me if your PC was restarting randomly or when you were working in Blender?
These restart is also happening when I am exporting 8k textures from substance painter with so many layers.
So I am not 100% sure if its something with blender 2.8 or 2.81.
And that motherboard test was a fail, he used a old full of dust core i3 2nd generation motherboard to test on my rig and like I said before the first time this software crashed but the PC didn’t restart for the second time we faced black screen problem.
I am guessing it can be a motherboard issue.
Also like richard said above his PC was restarting just because of dust maybe this is happening with me as well.
That little shop don’t have any unpacked good motherboard to test on my rig, so I need to find another PC to test my graphics card and power supply in it.
Maybe from a friend who has a decent PC to test on my rig. If it still restarts then I am guessing something is wrong with AMD driver or with their gpu.
And I will keep everything updated until I found the solution.
And thank you very much for replying my every comment, let me know if you find anything or think of something 
Yes, that is why we assumed HW problems. Could still be windows bug too, but if you have tried different windows versions or even OS’s other than windows and it still hapened then it’s probably not windows.
So if we have ruled out windows and HW then it’s probably the software. Substance may have an issue of it’s own. Or it may be that you have ran substance concurrently with blender each time and it’s still blender that’s causing it(or vice versa).
I’m still inclined to think it’s hw though. If you only had a non-polaris GPU to test with.
Edit :No need to read the comment below -_+ He made a typing mistake. he meant his pc didn’t restart while tried to export 8k maps.
And a friend of mine said he can help by giving his pc, so i can test
Yesterday i sent that SP file to one of my friend, who’s running i5 7th gen, gtx 1050ti, 8gb ddr4 ram and corsair VS450.vs550 i think.
And yes he said his pc restarted when he tried to export 8K maps. But didn’t face any restart when used that 4px tiles in that blender scene.
But for me it doesn’t happen all the time when i change that tiles size to 4px. sometimes it’s instant and sometimes it doesn’t happen unless i keep changing 2px to 4px.
And his pc is not even old like mine (maybe 1-2y old), my cpu and mobo is about 4+ years old, but gpu and psu i upgraded it 1year ago.
Okay now we should assume it can be a software issue? or can be something with hardware which can’t take too much pressure ?
You are talking about Substance Painter right? I can’t find any similar report when I search on Google, which makes this coincidence very strange of you two having the same problem with very different hardware. You should report this problem in the right place (Substance forum or wherever)
The hell man, he made a typing mistake
Actually his pc didn’t restart while tried to export 8k maps
Oh, okay…
So again i’m guessing my mobo has some issue then. 
His typing mistake almost ruined everything :_:
Well, it’s certainly not impossible, but if you can’t replace the mobo or possibly even mobo and cpu then you might just have to work in ways to avoid the issue until you have saved up enough to replace it/them.
Are you sure that a cpu can’t cause any problem like that? unless it’s over heating?
cause i won’t be able to change my cpu right now(I hope CPU is alright), but i can change the motherboard.
Cause i was planning about upgrading to ryzen series. but not right now
If you are getting a true hard reset it is definetely not a software or a driver issue. If it was a software or driver issue then you would either get a modernized bsod or freezing.
My guess is it is either the power supply or the cpu. It seems like your pc acting up when the cpu is heavily in use.
Yeah you are right about software shouldn’t cause any PC to hard restart.
But we ruled out the graphics card power supply ram and everything except The motherboard and CPU.
by saying CPU do you mean the board is facing some problem? cause I heard only overheating CPU should cause this restart but in my case CPU temp is fine. Also I tried stressing out the CPU but the PC didn’t restart.
maybe like others said the motherboard’s vrm is facing some problem.
Still can’t be sure, I was planning about testing my graphics card and power supply on another motherboard to know if my board is okay or not
Cause I already tried another graphics card and power supply on my motherboard but still those program caused my PC to restart
What is the exact/complete model of your motherboard?
Try updating your bios if you have not done so for a while and also reset it to defauls, probably a bios update will do it so.
You might also want to reseat your cpu with another thermal paste.
gigabyte h110m s2pv ddr3
And i5 6400
I heard bios update is risky, if something goes wrong then…
And yeah also i haven’t reapplied my thermal paste in years, cause temps were fine. (I always monitor temps)
I’m going to test with another pc, with my graphics card and psu.
If it works there, then I’ll update bios and reapply the thermal paste for the cpu. If still it’s restarting then I’ll guess my mobo is dying or something
Most motherboards these days have some kind of software for updating your BIOS, so it’s much safer, and easier. I used to have a gigabyte board, and I’m pretty sure it had a bios updater on the CD that came with it, though I’m sure you could also download it from their website.
And it’s happening very rarely nowadays.
But if you have UPS available, don’t hesitate to use it, just in case.
Uh, no. The classic methods are actually the safest so long as the user knows what they are doing. I.e. using the correct bios for the system and not letting the system be powered down by anyone else in the middle of the flashing/installation.
But if you really don’t know what you are doing then perhaps the wizards are slightly safer.