I'm building a PC with a Gigabyte B660 DDR4 motherboard, an Intel i5-12400, and an RTX 2060. I'm using a Cooler Master GT750M power supply, but the computer suddenly restarts whenever I run a graphics-card benchmark.
I tested the RTX 2060 and the GT750M together in an Asus TUF Gaming system with an i7-9700K, and they worked normally. I also tested my B660 system with a Corsair 750W power supply, and it worked correctly. The motherboard itself seems functional, and the graphics card and both power supplies work in the other configurations.
The same M.2 drive, hard drive, and other components were used during testing. Why would this particular motherboard and PSU combination cause restarts under GPU load? Is there a compatibility or power-delivery issue I should check?
1 Answer
Check Windows Event Viewer under Windows Logs > System and look for the critical error recorded at the time of the restart, especially a Kernel-Power event. That can confirm the system lost power or reset unexpectedly, although it usually won’t identify the exact faulty component. Also check that the 24-pin motherboard cable and the CPU and GPU power connectors are fully seated, and make sure you’re using the correct modular cables for that specific power supply.

I haven’t checked the Event Viewer yet. The graphics card and PSU both work in another computer, and the motherboard also works with a different 750W PSU, so I’m trying to narrow down why this combination fails under load.