When the CPU fan picks random RPM's

[still_learning]

I apologize in advance for the long post, but I'm trying to figure this stuff out alone and I'm getting nowhere. Also, sorry for the 'noise' ratings, but I don't own any equipment to measure decibel.

I'm sure it's my ignorance, but I'm unable to read CPU fan rpm via any 3rd party utilities (AIDA64 and BurninTest Pro) or inside BIOS; however, I can view through IPMI View and IPMI web-interface. Also, I can't figure out how the system determines fan RPM and why it seems to change at random. Setting the Fan Mode via the web interface doesn't appear to do anything except kick the fan up to 3000 RPM on Full Speed or keep it at 1000 RPM on all other settings.

CPU - E3-1275v6 (retail HSF)
MB - Supermicro X11SSL-F

Loud - the noise that Foxconn fans hit on boot when they max out rpm.
Moderate - still audible from 1-2 rooms over, but not as audible as 'Loud', perhaps half of Loud.
Low - reached this only once. what I would consider audible in room, but not outside of room.
Quiet - what my i5-6500 is with retail HSF. I can barely hear it inside the case, even under load.

4pinCPU@Fan1, no case fans attached

Startup
Sometimes Moderate through BIOS, then Loud at Windows login prompt
Sometimes Moderate through BIOS and Windows
Sometimes Loud through BIOS, then Moderate at Windows login prompt
Sometimes Loud through BIOS and Windows

Idle
No change

100% load
No change​

4pinCPU@Fan1, 3pinCaseFans@Fan2/3/4

Startup
Same as above

Idle
Same as above

100% load
Same as above​

I didn't put this above, however ONE time the RPM of the CPU fan adjusted as thermals changed. It was Low (from startup thru login) until I started running AIDA64 stress test and it responded accordingly to adjust for CPU thermals. ALL other times it has seemed to pick random RPM's and just sat at those RPM's without adjusting.

Another note (perhaps relevant), randomly Windows informed me Wired#1 stopped working with this message: Windows has stopped this device because it has reported problems. (Code 43)

This is my first time building on a server-grade motherboard (building a little minecraft/ark gaming server for the fam and friends), so that aspect is new territory and I'm sure there is something/alot I'm missing. However, could I have a bad MB and/or CPU?

 

[i386]

You problem is probaly ipmi and slow rpm fans (cpu fan rpm <650?).

Do you have the spec of the fans you use (rpm or model name/number)?

 

[still_learning]

There are several model numbers on there, so I've attached a picture (hopefully). It's an Intel Retail HSF (Foxconn specifically). Thes best I can find for figuring out the FAN part number is Where Can I Find Intel® Boxed Processors and Fan Part Numbers?. That said, searching online only returns the Fan and Heatsink together, and I was unable to find individual specs. Still looking.

Also, you mentioned slow RPM fans and IPMI. Does IPMI have issues with fans below a certain RPM? I know assumptions are bad, but I was hoping retail HSF's would be supported without too much fuss.


*EDIT*
In case someone reads the thread with similar issue. I replaced the case fans with some 4pins, but because the Supermicro boards fan thresholds are high, whenever the fans would reach a low RPM they would be immediately spun up to .
The process would repeat over and over (low/high/low/high/etc). I had to set the motherboard thresholds manually with IPMITOOL.exe so the motherboard wouldn't spin the fans up to a ridiculous speed when they went into a low RPM.