Computer Artifacting Recently And Crashing My Computer In Some Games

[Muhc]

So currently when I'm in Dota 2 or Rocket League after being in a match for maybe 2-10 minutes my whole screen flashes and then my screen goes black and I can't hear anything and my whole computer is unresponsive. My computer is still on and running though. Forcing me to restart.

This seems to only happen in Steam because I have played hours of Overwatch while this has been occurring and it has never happened in that game.

This is also a recurring issue that I thought I fixed with a driver downgrade only for it to start happening again yesterday. I upgraded to the now latest driver update, but that didn't fix the issue.
I ran a Memtest last night that came back clear and upon restarting my computer and beginning to run Furmark I notice some red artifacting on my desktop.

I wake up this morning and as my computer is coming on I notice that black artifacting is now occuring on my screen as shown here

I'm assuming my GPU is dying and put in an RMA request last night, but just came here for a second opinion.

Also my temps are normal (~70 degrees) except for Furmark obviously (~86 degrees).

EDIT: Now whenever I restart my screen will artifact as I move my mouse around it until eventually my screen flashes black and then says "Default WattMan settings have been restored due to unexpected system failure."
This also happens whenever I open MSI Afterburner my computer does the same thing until I get the same message. Here's a picture of the artifacting


Link to my unanswered reddit post if anyone is interested

Link to when it originally started happening

My Build:
PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i5-4460 3.2GHz Quad-Core Processor (Purchased For $147.62)
Motherboard: MSI H81M-E34 Micro ATX LGA1150 Motherboard (Purchased For $40.41)
Memory: Kingston 8GB (1 x 8GB) DDR3-1600 Memory (Purchased For $26.12)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive (Purchased For $54.68)
Video Card: VisionTek Radeon R9 390 8GB Video Card (Purchased For $240.68)
Case: Raidmax Vortex ATX Mid Tower Case (Purchased For $35.00)
Power Supply: EVGA 600B 600W 80+ Bronze Certified ATX Power Supply (Purchased For $35.11)
Operating System: Microsoft Windows 8.1 Pro OEM 64-bit (Purchased For $20.00)
Case Fan: Cougar Vortex PWM 70.5 CFM 120mm Fan (Purchased For $14.79)
Case Fan: Cougar Vortex PWM 70.5 CFM 120mm Fan (Purchased For $14.79)
Monitor: Acer V246HLbd 24.0" 1920x1080 60Hz Monitor (Purchased For $80.00)
Total: $709.20
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-03-16 14:55 EDT-0400

 

[DRagor]

You could check different monitor as well as monitor cables just to be sure, but it indeed looks like GPU problem.

 

[DRagor]

Copy from PM: "So I just discovered something whenever my computer restarts it will flash artifacts on the screen and then my computer will flash black and my Radoen Settings will notify me saying that "Default WattMan settings have been restored due to unexpected system failure."

This also happens whenever I run MSI Afterburner.

Would this still be a GPU issue or perhaps a PSU issue? "

PSU problems rarely cause things like artifacts on display. If you had problem with PSU, you would most likely suffer hard freeze when playing games. Obviously, bad PSU cannot be ruled out without testing, but chance is rather small.
I just hope you don't run WattMan and Afterburner at the same time - it could create conflict.