I wanted to tell somebody I figured out my overheating problem.
I have an XFX RX580 8gb graphics card. It would suddenly overheat and the screen would freeze while playing certain games. I could play as long as liked if I was playing Portal or Half Life, but something like FarCry 3 or 5 would crash after 30 minutes to an hour. I'm a casual gamer so that was no big deal to me. Meh. I just rebooted and started over.
I recently downloaded FarCry 4 and it would freeze almost immediately. The RX580 was well within the hardware requirements of the game. I had upgraded from a 2gb RX560, so I thought I was good. I tried a clean uninstall of the video drivers. I replaced my motherboard. I got a bigger 750 watt power supply. I upgraded my CPU and bought a water cooler. Nothing worked.
Since the graphics card was new I didn't think it could be the problem, but that's what everyone seemed to think it was. So I took their advice and pulled the card apart cleaned off the old thermal paste and reapplied it. The other chips had thermal pads on them; kind of a gummy gray stuff. I left alone. Dropped all of video settings as low as they would go. I downloaded MSI Afterburner so I could monitor the heat of my GPU and, for a little while, it did okay. I could go for 15 or 20 minutes before screen freeze.
I couldn't imagine why it was still freezing. I know older games are sometimes more resource heavy but my hardware was above average. I went through my computer again, reseated the cards and memory sticks. Reapplied thermal paste to the CPU.
Then, just for the hell of it, I pulled apart my RX580 one more time. I cleaned off the old thermal paste leaving the gray gummy stuff and realized there was one chip that wasn't making contact with the heat sink. There was supposed to be a thermal pad there, but it was missing. I had put paste on it the last time but it wasn't making contact.
I had an obsolete video card that I took one of the thermal pads out of and installed it on that one chip in my newer RX580. Now it never overheats. I can play FarCry 4 with ultra video settings and it rocks.
Windows 10 pro
Ryzen 7 2700x
MSI B450 Tomahawk