Question RX 480 usage spiking, game stutter, crashing

[pgfunny124]

Recently my MSI RX 480 8G Gaming X card seems to be having some issues.
I noticed that I was having odd stuttering issues in games that normally ran fine, (hitman, gta v) without having changed anything.
When checking radeon software, the gpu usage seems to be oddly up and down. (noticed this spiking while playing uno, other games seem to stay around 95-100)
My PC would also sometimes freeze and turn both of my displays black and require a hard reset to get video back.
This crashing happens especially when trying to run the user benchmark graphics section.

I've tried reseating the card, reinstalling the radeon software & drivers, I'm not sure what else to try to do.
Any ideas?

Thanks.

Image of strange gpu usage graphs in radeon software:

https://imgur.com/a/ciJ6hhQ

View: https://imgur.com/a/ciJ6hhQ

 

[Metal Messiah.]

Kindly provide FULL PC specs. Most importantly the Make and Model number of your power supply unit/PSU.

What's the GPU TEMP when there are spikes/crashes/instability ?