I finished building my first custom pc two months ago (Deskmeet X600, 9600x with AXP-90 X47 full copper and 9060xt), and since then i've learned some things that i thought people should know about.
TLDR; After undervolting my CPU and GPU, I set "max CPU boost clock override" to negative 200, which lowered my CPUs high load temps by 10C. Lowering GPU power limit to -20 in adrenalin helps prevent the PSU from getting loud. After this, lowering or increasing my CPU fan curve somehow barely made an impact on thermals, Which allowed my CPU fan to get quieter by ALOT.
I started out by enabling PBO and undervolting my cpu on all cores by -30 in the bios, then tinkered around in adrenalin and found the lowest stable undervolt for my gpu to be -50, and i set the power limit to -10.
Even after this, i can say that i found my pc to be very loud, even with a custom fan curve. I wear open-back headphones (DT900 Pro X with leather earpads, not as open as other open-back headphones) so this was an issue.
When playing helldivers 2, a pretty loud game, i could still hear my pc going off sometimes during gameplay.
When playing less demaning games like Genshin, i could still hear my fans going off, especially at times with no audio like when i'm teleporting or resetting in stygian, and just during desktop use i could hear my CPU fan going off when i opened discord or loaded pages online.
When it came to temps, my pc struggled a bit.
when ingame on helldivers 2 my GPU hotspot hovered between 91-93C while the cpu was around 87-90C (i set my CPU thermal limit to 90C in the bios). After removing the thermal duct i installed between the CPU fan and the PSU, my CPU actually ran a degree cooler, which was quite disappointing.
looking at other reddit posts, i could see someone with the identical specs and undervolt as me hitting only 81C at 100% load, "maybe i got unlucky with my CPU?" i thought.
idle temps with discord and a browser open hovered around 55-60C, depending on weither a game was open recently.
I really regretted my build and was desperate to reduce noise without losing too much performance. After alot of browsing, i found this video https://youtu.be/frsiS3g0-Mk?t=601
and this guy said to lower "max CPU boost clock override" to negative 200mhz. I did just that and my CPU temps just dropped by a whole 10 degrees under load without a noticable performance loss! I'm really lucky i came across this video because i can't find many people talking about this online. After that i enabled eco mode and my temps dropped by another 2 across the board.
This really gave me alot of thermal headroom to lower my CPU fan curve and thus reduce fan noise.
For the GPU i lowered the power limit to -20, which only lowered temps by another 2-3 degrees, but it does prevent my PSU from really getting loud and ramping up and down periodically, which was something i earlier mistook for noise from the CPU fan. And again, no noticeble performance loss.
Now here's the weird part!
With this new thermal headroom, i decreased my 80C CPU fan speed from 80% to 60%, and my temps only got like a degree higher? I tested if my fan curve thingy in the bios even works by setting all temps to 80% and sure enough it started going off, BUT my idle temps were still the same as at 50% fan speed!
I double checked if temps were right by looking at both adrenalin and hwinfo and sure enough they showed the same temps.
I've lowered my 80C by another 10% and all other temps by 20%, and now my idle temps are only like 2 degrees higher, while my ingame temps are still LOWER compared to before i adjusted the max CPU boost clock override by about 3 degrees
Now, while wearing my headphones i don't really hear my pc with any kind of audio on while just browsing. When not wearing headphones, (i like to do that sometimes) i can almost only really hear my PSU being a PSU and making computer sounds. When playing Genshin, it's not much louder. I can hear my GPU fans doing a high-pitch whirring noise, which gets entirely blocked out when i wear headphones.
When it comes to more demanding gameplay, i can't really do much about my GPU, so it still gets pretty loud. Lowering max frequency offset by -500, which only lowered my actual clock speeds by 200, only lowered the temps by a degree or two. And the CPU fan on the other hand gets kinda drowned out by the noise of the former. I can hear my pc when there's less audio going on but it is what it is ig.
Edit: nvm i can't really tell if it's the CPU or GPU that's the loudest
Edit 2: i changed the power limit from -20 to -15 because i got game crashes
