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Discussion EPYC builders thread

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Junior Member
Feb 20, 2013
Hi folks!

I got to build an Epyc Rome workstation (target: deep learning research), and I have a specific requirement: the board must allow sleep (suspend-to-ram) or at least hibernation (suspend-to-disk).

I already had an EPYCD8-2T, and I had to return it since there was no way to put it into sleep.

Maybe you can report if your own boards do allow sleep/hibernation?

Thanks in advance!


CPU Moderator, VC&G Moderator, Elite Member
Super Moderator
May 16, 2002
My 5 EPYC systems are always@100% use, so no idea. But 3 of my 5 motherboards are the EPYCD8-2T


Elite Member
Dec 10, 2016
Exactly like Markfw, I have no use for sleep or hibernation.
I set up my swap partitions too small for hibernation, hence can't test it unless I add another disk.
I now tried sleep (initiated it from the respective button on the login screen) and it went to sleep but I did not find a way to wake it back up. I had to power-cycle it in order to recover.

(This is dual EPYC 7452, Supermicro H11DSi, openSUSE Leap 15.2 with kernel 5.3.18.)


Elite Member
Dec 10, 2016
For anyone with Supermicro boards with BMC (AMD boards as well as Intel boards), here is useful information on fan control:

H11DSi features Supermicro's infamous problem with slow-spinning fans: The BIOS misdetects fan failure all the time and periodically spins the fans up, then down again.
My workaround:
Use a triple fan adapter to plug the small and faster spinning 40 mm fan and the two slow spinning 140 mm fans into a single fan port, and show only the RPM signal of the 40 mm fan to the board.
I am still using the workaround of disconnecting the RPM sensor wire of fans which have a too low minimum speed. It's a bother.

The board firmware has got these fan speed thresholds:
  • "Low nonrecoverable": less than or equal to 300 RPM — If at least one fan runs at this or a lower speed, the BMC firmware logs a respective event, and the board ramps all fan headers up to 100 % PWM duty cycle.
  • "Low critical": less than or equal to 500 RPM — This just causes a respective event being logged.
  • "High critical": 25400 RPM; I don't have fans which would go that high.
  • "High nonrecoverable": 25500 RM; again I don't know what will happen at that threshold. Best to approach such systems only wearing ear protection and, importantly, certified eye protection.
Fan speeds are represented in the firmware in steps of 100 (i.e. obviously by an internal 8 bit value between 0…255).

I now tried the Noctua NA-FC1 fan controller. This one has got a "no stop" mode in which it controls the fan such that at least 300 RPM are maintained. Unfortunately, the Supermicro firmware still asserts "Low nonrecoverable" state when a fan is in this mode, and applies the mentioned 100 % PWM duty cycle panic.