it’s funny that you’re using gentoo and want to avoid recompiling since the last time i used gentoo was on a single core, first generation imac and it literally took me 3 days to compile the kernel along with the drivers that i needed to get the apple/ppc architecture to work correctly
it got so hot that i couldn’t even touch it for another day. lol
yes, exhaust all of the the other troubleshooting advice that the others gave you in this post before going down this rabbit hole; i only suggested it because it worked for me the last time i used gentoo, in my example.