Manual Control of Dell PowerEdge Fan Speed (12G, 13G) August 6, 2021
Tips/Tricks
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If your like me and have a home datacenter, or have a bunch of Dell servers a small home lab, the fan speed curves in the iDRAC are very aggressive. They are normally used inside data centers where audio reduction is not a priority. Being said there are some simple tweaks you can do to manually set the fan %PWM or duty cycle.

Now this will reduce the fan speed to a set value, but you will need to monitor the temperatures to ensure no overheating.

I found in my testing with a intake temp of 72-74F that 33% was plenty to keep the CPU’s happy at arround 99-100F or 37-39C

Process is quite simple.

  • First, enter the iDRAC WebUI and Enable IPMI, this will allow the impitool to access the system
  • Second, create a new user, as the root (default) user cannot run IPMI commands
    • This user will need Admin access to LAN User Privilege’s
  • Fourth, connect via IPMI and run the following
    • This will Enable the use of the Manual Fan Control
ipmitool -I lanplus -H [ip] -U [username] -P [password] raw 0x30 0x30 0x01 0x00
  • Next to set the Fan Speed to 33%
ipmitool -I lanplus -H [ip] -U [username] -P [password] raw 0x30 0x30 0x02 0xff 0x21
  • The last section “0x21” is the fan speed in hex, if you want a different speed, convert your wanted % from 10 to 100 into hex using a converter, such as https://codebeautify.org/decimal-hex-converter
  • Lastly, check IDRAC to see your result
  • To disable Fan Control and return to normal IDRAC profiles/curves
ipmitool -I lanplus -H [ip] -U [username] -P [password] raw 0x30 0x30 0x01 0x01

Useful links:
https://www.dell.com/community/PowerEdge-Hardware-General/Dell-ENG-is-taking-away-fan-speed-control-away-from-users-iDrac/td-p/7441702
https://www.reddit.com/r/homelab/comments/d0422n/to_anyone_considering_or_using_dell_14th_gen_for/

Notes:
Changes only work for 13th gen and below unless you downgrade the iDRAC firmware to a very old version on a 14th gen