Feeling a bit silly about this, but I've had a sudden issue that started yesterday evening and I have no idea why it began. My issue occurred playing a game where the game started playing with some serious slowdown. At this time, I heard my CPU fan spin down. Thinking the game was the culprit, I quit out, only to notice similar lag even in basic functions. Running performance tests showed me that the CPU is running at a constant 75C but the fan on physical inspection is merely running idle. I can't even seem to push the CPU usage beyond this level, so my only conclusion is that the CPU is suddenly deciding to throttle itself to maintain temp instead of ramping up the fan. I'm not sure if there's some kind of hotkey that would flip this logic, but even after reboots I've seen no change. Any advice on what course of action to take next?
#CPU throttling to maintain temp instead of fan ramp?
gaunt laurel
vivid badger
Feeling a bit silly about this, but I've had a sudden issue that started yesterd...
this is called thermal throttling and basically every CPU has that capability, but 75 C isn't that high as most at at about 95 C
could you supply the hardware specs?
idle pasture
You can also check your motherboard BIOS. Check for Smart Fan settings. See if it's on. Smart fan should maintain temps without any additional tweaks needed.
gaunt laurel
yeah, my BIOS is set to do so, but even when setting the BIOS to just go full throttle it just doesn't seem to. Even on a CPU stress test it fails to manage any kind of fan speed increase, instead opting to throttle.
Specs are Ryzen 7 7700, 64GB DDR5 RAM, RTX 3060 LHR.
What really threw me off is it has been configured the same for over a year and only suddenly midgame decided to play this throttling game with me and yet still persists after reboots. I first thought the fan died or something, but no, it's running at a solid 500 RPM (so, basically idle speed).
idle pasture
What's your setting on for your GPU and Power? Is it on performance or adaptive?
gaunt laurel
performance for power - toggled the nvidia between on-demand and performance with no difference
idle pasture
Is your CPU fan wire connected directly to your motherboard fan port?
gaunt laurel
it is
as said, it's been functioning properly for over a year with the expected fan ramps
idle pasture
Do you have PWN on for your fans? It lets the PC decide when to ramp them up.
gaunt laurel
no separate controller card or anything like that, no
idle pasture
I'd say check it for dust. Recheck, if needed replug the wires. Make sure PWN is on in your BIOS. Check the smart fan curve. Edit it to be more sensitive. Finally check your CPU idle temp when logged in.
gaunt laurel
even idle it stays at a constant 75-77. The one thing that I did get concerned with was the PSU, just because the PSU's fan isn't spinning, but I don't know if that's just because the PSU I think has adaptive fan control on its own.
the PSU does not feel all that warm, so that may just as easily be the reason for no fan spin there
the strange thing is the BIOS fan settings don't seem to matter - I set it to full speed and it still runs the same.
idle pasture
The PSU won't spin up unless it needs to. They are designed to run luke warm on idle.
gaunt laurel
that's what I figured
idle pasture
If it's 75-77 at idle... What's your cooler?
idle pasture
Evo? No water cooler?
gaunt laurel
negative
idle pasture
Is it the stock cooler that comes with AMD's CPU?
gaunt laurel
no, it's one of Noctua's
idle pasture
Dual fan or single fan?
idle pasture
Those are horribly small.
gaunt laurel
basically the biggest one I can fit into this case, all said and done, but I've not had any issues 'til now
idle pasture
What were your idle temps prior?
idle pasture
40 is good. I'd reapply the thermal (turn off PC) paste and see if anything changes.
gaunt laurel
my big thing was wonder if I did something strange to trigger some kind of Eco mode or something
idle pasture
I will be frank though. Those types of coolers run stupid hot. I had one push near 80c on Everquest 2. I upgraded to a dual fan, evo. Problem solved. I'm currently using a dual fan noctua.
Even with an eco mode. It shouldn't be push heat on idle.
gaunt laurel
I wish I could go dual, but this is a small mini-ITX with no depth whatsoever, so I can't really fix too much more
idle pasture
At a bare minimum. Change out the paste. See if it fixes it.
Look for blockage in the case. Maybe it's not getting enough air.
gaunt laurel
ironically the case is as open as it can be (Fractal Design Terra) 😅
open does not even begin to describe it
idle pasture
Hm... That could be the GPU back plate heating up the CPU.
Well... It shouldn't do that on idle. Try the heat sink first.
gaunt laurel
yeah, I'll do that.
idle pasture
CPU thermal paste reapply. Then check the temps on idle.
gaunt laurel
hopefully that'll do it, then. At least I know it isn't something dumb I did in Mint that caused it to go this route. That was my big concern.
idle pasture
Your GPU will be outputting 38-41c on idle. So that wouldn't cause 70+
Look for any blockage, dust, anything that could be getting in the way. While applying the paste again.
gaunt laurel
GPU is idling at around 50
idle pasture
Hm... That case sounds like a bad design. Maybe it is the back plate of the CPU and GPU heating up the center.
gaunt laurel
fans aren't even running on the GPU at the moment
idle pasture
GPU has the same setup as the PSU. Fans won't turn on until the temps are high enough. For the GPU it's around 60c.
gaunt laurel
aye
I HAVE heard this thing ramp up like no tomorrow before, so I know it's capable. Heck, it was running pretty good right up 'til it just up and dropped off and started throttling
hearty tusk
I HAVE heard this thing ramp up like no tomorrow before, so I know it's capable....
i got similar issues with my laptop, all in LMDE6. after a certain mandatory software update, the fan started spinning much higher than before, even without load. after a second or third update, the fan went to normal behaviour. just like that. 
this cycle repeated several times, not exactly update after update, but close to.
gaunt laurel
Safe to close - issue was entirely hardware. Swapped out the NH-L9a-AM5 with the NH-L9x65, both a better heatsink/fan AND better aligned for this mobo design (vertical instead of horizontally aligned). Temps are sane again (35-40 idle, capping at 70 under load). Guessing it was a perfect storm of the fan dying, dust accumulating, and poor heatsink/fan setup.
idle pasture
I knew it! Those coolers are not made for high end. You are better off upgrading to a mid/full tower in the future. All that space is for proper cooling. I would consider a dual fan Noctura later. Just make sure the next case has the space. Modern CPUs have abandoned low power draws for higher performance.
If the case allows the room. A proper water cooling block could do the trick.