So I was changing the case fans, after I put everything back together, I forgot to plug in the power for the GPU. I turned the pc on and I saw the white LED on GPU power port lid up and heard the fan spins like crazy (I don’t know if it was the CPU fan or the GPU fans), I panicked and immediately turned off the power supply.
Everything happened in less than 2 seconds, I’ve run some stress tests and gamed for a few hours and nothing bad happened (yet?) so I assumed everything is still fine (for now?).
What happens if I had left it on like that for longer? And why did the fan ram up like that?
Could have been any of them, but I believe the one over the CPU would be my best bet. It’s just a check to make sure it’s working, and if it fails you will most likely see an error at the end of the post, which is right before the OS loads. GPUs are not required for most PCs to function unless you got a motherboard that does not have an on-board display output, in which case you just have no way of hooking up a display. If this was the case you could still get to the PC if you knew how to remote into it as well.
my motherboard has display output but my CPU doesn’t have an integrated GPU so I need the graphics card for output.
btw, it just popped up in my head: What if I plug in the power without turning the PC off? Will something bad happen?
The physical copper wire connection in the plug and socket is not instant and as its wiggled around, breaking and making connection in quick succession, will likely cause voltage and amperage spikes which can damage components on the gpu. In the best case nothing happens and you have a black screen until you power cycle your pc. Worst case is a dead gpu core.
Wasn’t me, but I would assume you got down voted because it’s not possible for your mobo to have a display output without having an integrated GPU.
That display output is literally a component of the onboard gpu