really bad frame drops on certain games

So, I’ve been trying to play marvel rivals and my game runs really bad. I set everything to the lowest graphic settings that i could and it hardly seems to help. i set my max frame rate to be 100fps and it does seem to help a little, but i get this insane frame drops where it’ll go down to like 10 frames for a second or two and then jump back up. it happens every 5-10 seconds and it’s made it really hard to play.

I checked the AMD software to see what was going on and the GPU usage will be at like 70% then drop down to like 10% then back up again. Whenever that happens my frames drop too. I checked and the power usage drops down too, but not as low. The temperature usually doesn’t get very high to be concerning so I thought that it’s not my power supply, but I’m still unsure.

A couple days ago my whole screen went black and everything stopped working. I tried turning off the computer but it took a minute. Since that happened i kinda just assumed its probably a power supply issue and im trying not to play anything too intensive.

Whenever I play overwatch, the game runs real smooth. Any frame drops are only like 20-30 frames at most at 144fps. And they happen for like a split second. I notice the utilization does drop down still but it’s much less than marvel rivals.

All my drivers are updated and so is my computer

Any help would be greatly appreciated

My specs: AMD Radeon RX 6700 XT AMD Ryzen 7 3800x B450 Tomahawk Max II 500gb SSD 16gb of ddr4 ram 650w 1080p 2 monitors