Regarding mini PCs; Beware of RAM overheating!

I bought some Minisforum HM90 for Proxmox selfhosting, installed 64gb RAM (2x32gb DDR4 3200MHz sticks), ran memtest first to ensure the RAM was good, and all 3 mini PCs failed to various degrees.

The “best” would run for a couple of days and tens of passes before throwing multiple errors (tens of errors) then run for another few days without errors.

Turns out the RAM overheated. 85-95 C surface temperature. (There’s almost no space or openings for air circulation on that side of the PC). Taking the lid off the PC, let 2/3 computers run memtest for a week with no errors, but one still gave the occasional error bursts. RAM surface temperature with the lid off was still 80-85 C.

Adding a small fan creating a small draft dropped the temperature to 55-60 C. I then left the computer running memtest for a few weeks while I was away, then another few weeks while busy with other stuff. It has now been 6 weeks of continuous memtest, so I’m fairly confident in the integrity of the RAM, as long as they’re cold.

Turns out also some, but not all, RAM sticks have onboard temperature sensors. lm-sensors can read the RAM temperature, if the sticks have the sensor. So I’m making a Arduino solution to monitor the temperature with a IR sensor and also control an extra fan.