Question My GPU starts to overheat when plugging in my second monitor.

[bubbabeef]

I've used these 2 monitors for a very long time. I bumped my shelf and my PC came unplugged. I went to turn it back on, it boots up fine, but I notice the fans are at full speed. My computer black screens, but sound is still playing from youtube. This has happened before, and a restart/5 minute wait fixed it. Now if I boot up and I only have my main 1440p plugged in, everything is stable. The moment I connect the HDMI for the second monitor, I can watch me GPU temp rise 1 degree a second until it hits about 90 and the thing black screens. If I unplug it before it gets to 90, temps stabilize.

Just checked, and i can have the opposite monitors plugged in and the same thing happens. So basically it starts to heat up when I have 2 monitors plugged in, and this just started after an accidental shut down by kicking the power cord. It's happened before but went away on its own.

Any ideas?
running 2080ti water cooled
ryzen 3700x water cooled
16gb ram
windows 10

 

[hotaru.hino]

Where does the temps stabilize to with one monitor plugged in?

 

[bubbabeef]

Between 60 and 70

 

[hotaru.hino]

If this is happening when you're just playing YouTube, especially when on a single monitor it's floating around 60-70, this sounds like a problem with the cooling system. For a reference point, my video card (a 2070 Super) is floating at around 40C on air cooling with the fans spinning about 25%.

Otherwise when you plug in another monitor, it's likely that the video card is kept in an elevated power state. This usually happens if your monitors have refresh rates that aren't divisible into each other (e.g., 144Hz and 60Hz).

 

[bubbabeef]

Interesting. I let it sit off overnight and boot up this morning. It stable about 30C with both monitors plugged in. I switched my 144hz to 120hz. Not sure if that was what made the difference, or reinistalling graphic driver and letting it sit overnight.

Regardless, what you said makes sense. Only thing is, this just happened randomly. Any idea why the cooling system would just malfunction due to a shutoff? My fan radiator setup isn't perfect. I'm going to spend some time reworking that i think, now that i know it's at least partially a heat issue.

Not sure why it's been totally fine all this time and just now is giving me trouble.

 

[hotaru.hino]

It's a known problem that video cards work harder when the monitors have mismatched refresh rates like that. I'm going to guess to keep timings as easy to work with as possible, the video card acts as if it's driving a single monitor that's the least common multiple of 60Hz and 144Hz, which is 720.

Since you said you bumped your computer, it might be good to check all the fittings and cables and such. And if you want, reapply any thermal paste (it shouldn't matter, but if you're doing basically routine maintenance anyway...)