My TrueNAS Core runs on a Supermicro A2SDi-x-HLN4F board in a multibay chassis that has a bridge containing 4 identical Fans to cool the drives and the board. I put a Noctua PWM fan on the CPU to get better cooling than just from the passive heat sink.
From what I so far understood from the lackadaisical Supermicro manual and bits and peaces found here and there:
Cooling zone 1: Fan headers 1-3, controlled by the CPU Temp sensor, the CPU fan is supposed to be connected to fan header 1
Cooling zone 2: Fan header A, controlled by the System Temp sensor? (unclear, haven't found ANY information on what sensor is used to control this fan header. Anyone knows more details?)
This is how i connected the 5 fans (all sensor readings are from the IPMI web UI):
Fan header 1: CPU fan Noctua PWM, sensor reading: 1.300 RPM
Fan header 2: bridge fan 1, sensor reading: 1.600 RPM
Fan header 3: bridge fan 2, sensor reading: 1.600 RPM
Fan header A: bridge fans 3 + 4 connected through the Y-cable that came with the Noctua fan, sensor reading: 700 RPM
The temp sensor readings in "C degr" are:
CPU: 46
System: 46
Peripheral: 41
DIMM A/B 1/2: 46
Since none of the temp readings is significantly lower than the CPU temp I do not find any explanation why the RPM reading of Fan header A is just 700. Keep in mind that the bridge fans 3 and 4 are identical to bridge fans 1 and 2! (I do think I understand why the CPU fan runs slower as it is a Noctua)
Does someone have any idea what is going on? Is the reading just false, or why would Fan header A be set to just 700 RPM whereas Fan headers 2 and 3 are at 1.600 for the same kind of fans?
Your wisdom is welcome.
From what I so far understood from the lackadaisical Supermicro manual and bits and peaces found here and there:
Cooling zone 1: Fan headers 1-3, controlled by the CPU Temp sensor, the CPU fan is supposed to be connected to fan header 1
Cooling zone 2: Fan header A, controlled by the System Temp sensor? (unclear, haven't found ANY information on what sensor is used to control this fan header. Anyone knows more details?)
This is how i connected the 5 fans (all sensor readings are from the IPMI web UI):
Fan header 1: CPU fan Noctua PWM, sensor reading: 1.300 RPM
Fan header 2: bridge fan 1, sensor reading: 1.600 RPM
Fan header 3: bridge fan 2, sensor reading: 1.600 RPM
Fan header A: bridge fans 3 + 4 connected through the Y-cable that came with the Noctua fan, sensor reading: 700 RPM
The temp sensor readings in "C degr" are:
CPU: 46
System: 46
Peripheral: 41
DIMM A/B 1/2: 46
Since none of the temp readings is significantly lower than the CPU temp I do not find any explanation why the RPM reading of Fan header A is just 700. Keep in mind that the bridge fans 3 and 4 are identical to bridge fans 1 and 2! (I do think I understand why the CPU fan runs slower as it is a Noctua)
Does someone have any idea what is going on? Is the reading just false, or why would Fan header A be set to just 700 RPM whereas Fan headers 2 and 3 are at 1.600 for the same kind of fans?
Your wisdom is welcome.
