I fear, for either complex or uncommon reasons, that this could happen again and with worse consequences. Basically, I have had one session at abnormally high CPU temp readings (I don’t know yet if they were real), I did 2 fixes before starting next session (fix SpeedFan startup with Windows and, kind of inadvertently, slide the heatsink over the CPU, minimally but noticeably), and CPUtemps/readings are normal now. The best possible news would be that it was SpeedFan, but if it was something about the paste or the heatsink settlement, possibly I have to do something about this (like laying the case down on its right side when shutting down until the paste “cures”, or leaving it on for several days, I’m anything but expert in this really).
- processor: AMD FX8350 4GHz (Vishera, 125W TDP)
- motherboard: Gigabyte GA-970A-DS3P (chipset AMD 970 + SB950)
- case: CoolerMaster Centurion 5 (midi tower, 43.5 cm high x 48 cm long x 20 cm wide, front made of mesh, side racks for processor and cards, 120 mm exhaust fan)
- CPU cooler: Tacens Gelus Extreme (w/o ordinal; horizontal, full copper, wide fins, somewhat heavy, 3 heatpipes w/o direct contact) with upgraded fan
- CPU fan: Enermax Magma UCMA12 (120 mm, 1600 rpm, 69 cfm)
- case fan: Scythe Slipstream 1900 rpm (120 mm, 1900 rpm, 110 cfm)
- 16 GB RAM in 2 modules
- GeForce GTX 750Ti
- EVGA 500W PSU
- 2 DVD drives
- SDD and HDD
- Windows 10 pro 64bits
Normal situation at idle:
SpeedFan and the BIOS agree in this (room temp is 16ºC):
CPU fan: 1680 rpm (not regulated)
Case fan: 1070 rpm (regulated by the motherboard)
Problem: processor seen at up to 91ºC with SpeedFan during a Windows update load.
Today I’ve switched on the computer after 48 hours off (first time this long) and I’ve seen the processor at up to 91ºC (SpeedFan reporting, rest as above) while loaded at 80-100% (w/o signs of throttling) likely for the calculations of a Windows update. I fixed a problem with SpeedFan startup with Windows, I rebooted to the BIOS and it reported 75ºC. After shutting down and switching on again, values returned to normal.
When seeing those temps, I opened the case to see the fans and touch the CPU heatsink, that was only slightly warm. With the rig off and unplugged, I did more concious checks and was able to slide a bit the CPU heatsink.
Afterwards I tried compressing a big folder (3 GB) with WinRAR and CPU temp did peaks at 65ºC only (the rest of temps did rise 1ºC if at all, what kept my exhaust fan at those 1100 rpm although it can do 1900, but I think that gaming should rise chipset temp and case fan speeds; I could also place a Slipstream 1600 instead and leave it w/o regulation).
- SpeedFan: I use it only to see temperatures, rpm etc. These first days of the build I’m configuring SpeedFan startup with Windows Task Scheduler and w/o doing additional reboots. This time it started (unlike in my previous attempt 2 days ago) but complained about some drivers not being loaded and didn’t load. I know the fix for this is setting a delay (task → triggers → edit trigger → advanced → delay for 30 seconds). Now it’s already working well, but it wasn’t in the problematic startup some hours ago. I added the setting to the task and launched it successfully (to test the task and to launch SpeedFan).
¿Could a badly launched SpeedFan misconfigure the CPU temp reading until next shut down?
- Thermal paste first times / Heatsink attachment: might the thermal paste have turned too solid or whatever for conducting well, during the 48 hours the rig was off before the problematic session? This flat doesn’t have heating and temps in the night in this room drop to 10-12ºC.
If it matters, the paste is Arctic MX4 bought in 2020 and never used before. I cleaned both surfaces with cotton and pharmacy ethanol, and I applied a small quantity in the center of the processor.
While inspecting the heatsink attachment with the computer off between the two sessions this morning, I was able to slide the heatsink over the processor a bit. This also happened while unmounting the cooler from its previous attachment, a Brisbane (ancient AMD dual core with 65W TDP, for which this cooler was overkill and never was hot; btw everything was different in this 2007 build: I used the stock paste, the flat had heating (in winter) and it was summer, and I spreaded a layer of paste instead of putting a bit in the center, what has made me work to clean the excess some days ago after the unmount) that I used just before the unmount (a common advice for softening the paste and easing the heatsink removal).
So the heatsink attachment has clearance and its contact surface is totally even, like processor’s. If the paste is fluid the heatsink can slide a bit. Is it critical? Might the paste flow on its own? Does it depend on if the paste has “cured” yet?
Amount of pressure? Moderate, not excessive. I have done mounts applying more force, but I wouldn’t say “weak”.