I’ve installed a brand new heat sink (came with thermal paste applied, and I tightened it down well) and a new fan. The CPU is still idling at 74° C. The PC is in a cabinet with an ambient temperature of 81-83° F (27-28° C).
Apparently my only remaining option is to check the BIOS and hope that C-States and Intel SpeedStep need to be turned on (they should be on by default though). Otherwise there doesn’t seem to be any remedy. Does anyone have any ideas?
What temperature are you measuring?
74C at core might not be that off and can be hard to lower too.
74C at top/heat sink might be a bit high, but might also be fine in some cases.
I know the System Monitor showing 74° C is like 20+ degrees too high. I’m not sure exactly what it measures; it’s the standard measurement that the integration provides. I have another HA host machine that is at a constant 20% CPU utilization and it’s only 56° C.
Here is what my HWMON is showing in the 74° C machine:
Is heatsink hot (like 70 °C hot) or way lower? If lower: how much of that paste did you apply? Hopefully not all… only a thin even layer must be applied. If there’s too much paste then effect will be opposite than wanted (less efficient cooling).
But that’s not very likely - if you tightened it well then paste should protrude out… perhaps CPU is “constantly doing something” ?
Thank you for the reply. I will re-apply MX-4 when I get a chance and let you know how hot the heatsink is when I open the case. I do recall that, when I replaced the heatsink a few days ago, it was rather hot when I pulled it out. The entire inside of the computer case was quite hot.
Another thing to mention: When I received this computer (bought used off eBay) it came with a 256GB NVMe loaded with Win11. I was going to replace it with HA, but I did try booting it to Win11 just for kicks and it kept running into issues during boot. I didn’t mind. But now I wonder whether there could be a hardware issue (motherboard?) that would have prevented Win11 from loading but isn’t such that HA cannot load …but then it just runs hot.
I don’t know enough about computer hardware to know the answer to that. I reached out to the seller and they said I can ship it back to them for an evaluation. I’m leaning toward doing that.
If you have applied way too much thermal paste as Protoncek hinted, then that is probably the cause.
A heatsink need as much metal to metal/die contact as possible.
The paste is not meant to go between the metal and the metal/die, because it conduct heat far worse than the direct contact.
The thermal paste is meant to fill the small air gaps where the metal to metal/die contact is not perfect, because the thermal paste is way better to conduct heat than air.
Check your fan speeds in the BIOS settings have not been turned down (sometimes done to reduce fan noise) and do a general dust cleanout of your case internals.
Any of your fans stopped or growling?
Your CPU will always run at temperatures above ambient - it has a lot to do. Check you do not have malware and bitcoin miners running in the background you may not be aware of. Treat any software supplied with equipment with caution, and maybe go back to factory settings to be sure.
Are any addon boards like a video card fan cooled as well? Are their fans running correctly?
Resetting your BIOS to default settings will bypass any overclocking attempts which can raise temperatures and produce unstable operation.
Check you have the latest updates, not only for your BIOS, but video card and Windows drivers.
I figured it out. TLDR at end if you want to jump ahead. Thank you all who have provided guidance.
I removed the computer from the rack/cabinet. Airflow is great in there, by the way.
I plugged it in on a desk nearby with an ethernet cable running from the router. No other peripherals. The CPU gave me a steady reading of 33° C. First, I left the lid off and observed the fan spinning. When I put the lid back on, the temp stayed the same, even after another 10 minutes at idle. The ambient temperature is only about 5°F cooler on the desk than in the cabinet… So then I thought, maybe the issue is related to the USB ports/devices.
By the way, I replaced the PC with a Pi5 in the cabinet during this time, and the Pi was giving me a reading of 39° or so while I was doing this, with all the USB devices plugged in via an externally powered USB hub.
Then I replaced the Pi5 and plugged the PC back in over at the rack, with the USB devices plugged in as well. Hot again.
So I unplugged one of the USB devices. I’m running Firmata on an Arduino Nano. When I unplugged the USB cable to the Arduino Nano, the temperature dropped precipitously; like 10° in seconds.
So then I tried the same Arduino Nano plugged into the externally powered USB hub, then plugged into the PC (to rule out USB power issues on the PC). Still hot.
Long story short…
TLDR; I had an Arduino Nano running Firmata plugged into the PC via USB. This paricular Nano was the cause. I’ve replaced the Nano with another Nano and there is no longer an issue.
