rx480 nitro 8gb frame rate spiking in games

[N333ch]

Hi guys.

Just built my first PC:

Sapphire rx480 Nitro 8gb
Ryzen 1700x
Asus Prime B350 plus
8gb ripjaws ram ddr4
CM V650 (psu)
CM Hyper212 LED turbo (heatsink)


Everything seems to work fine until i boot up a game, even a very graphically inexpensive game like LoL, and the frame rate spikes from 330+ fps to 10-20 fps and the whole screen is flashing black every 3-5 seconds.

GPU temp was around 50c during this, fan was on, no noise.

CPU temp was around 65 - 70c but I just read that ryzen 1700x has a 20c offset on its temp reporting, so this might be nearer 45 - 50?

Ive reinstalled all drivers with DDU.

How do I go about debugging this issue? I'm very new to this so I'm not sure which metrics are important.

EDIT: i just ran overwatch and it crashed with the message "your rendering device has been lost". Something wrong with the GPU?

 

[elbert]

Sounds like power supplies to the GPU is iffy. Try furmark with GPUz and watch your power..
http://www.ozone3d.net/benchmarks/fur/

 

[N333ch]

Sounds like power supplies to the GPU is iffy. Try furmark with GPUz and watch your power..
http://www.ozone3d.net/benchmarks/fur/

I ran that tool and the power draw was around 150w with GPU load at 100%. Temperatures went up to ~70c but fan speed was only ~30%

Are there any clues here?

http://imgur.com/a/82uu3

 

[elbert]

If you didn't crash the tells you the GPU is fine it's getting enough power. I would next look at software issue like bios updates, viruses, drive issues like sector errors, and possibly bad or corrupted windows install.

 

[N333ch]

If you didn't crash the tells you the GPU is fine it's getting enough power. I would next look at software issue like bios updates, viruses, drive issues like sector errors, and possibly bad or corrupted windows install.

Updated BIOS - no luck
Tried older GPU drivers - no luck
Reinstalled Windows - worked

Thank you