Games constantly freezes and stuttering
Games constantly freezes and stuttering
There's the issue, 97c is bad. Likely the card is thermal throttling to keep from damage.
I would dust the card and ramp the fans up in MSI afterburner. IF its still above 80-85c, id reapply new thermal paste to the R9 280.
Likely it wouldnt cause your symptoms.
Bad PSU could cause unexpected restarts, shutdowns, and blank screens.