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Fan noise for various ProLiant servers (ML110, ML150, ...)

Occasional Advisor

Fan noise for various ProLiant servers (ML110, ML150, ...)

Several threads (especially from a couple of years ago) ask support about the increased fan speed of the Proliant servers after the addition of PCIe expansion boards, like an additional SATA or SAS controller.

I own a ML110 G7 and in my case (as example) the standard fan speed was 13% without PCIe boards, it went up to 39% (three times the original one!!!) after the addition of a simple, non-RAID, SATA PCIe 4x card which produces basically no heat.


I have no experience with Windows and its drivers taking control of the fan speed, since the server is running illumos, but it appears I am not the only one.


Just to summarise:

- BIOS, iLO updates/resets do nothing: after a few minutes, the PCIe fan (in my case labeled "Fan 8") goes back to normal

- this is a "feature", HP plans (well, "planned", since the product is old) no changes

- the fan connector is technically non-standard (5 pins, where the two used for GND are shorted together to signal the presence of a fan connected), but very similar to a standard one: except for the additional, shorted GND, it's a normal 12V fan with SENSE from the fan and PWM speed control to the fan

- the BIOS does NOT read the actual value of the fan SENSE signal, as long as it is present: if the fan goes at a different speed than planned, BIOS is happy anyway. However take out that signal wire and EVERY other fan in the case will spin full-speed, but take out the fan connector completely and the motherboard will start beeping as if there were no tomorrow

- if you manage to place a fan speed controller (there are many available) that generates a new PWM signal, one you can actually set, while letting the fan SENSE signal go back to BIOS, you will be able to set the fan speed without having any additional trouble.


In my case I did that with a custom chip (fur fun...).

I checked the fan 8 speed on the whole last year and I noticed it never changed, even when every other fan was changing speed due to ambient or other sensors temperature, so I set the fan 8 speed to 20% (half the BIOS-imposed value, but still more than the original 13%). The temperature of the components in the PCIe zone (System board, PCI 1-4 Zone) either was unaffected or went up 1-2°C, meaning I have now a +7°C deltaT compared to ambient inlet temperature. Definitely acceptable.


Noise went back to very acceptable levels, no more whooshing all the time in the background, and less dust introduced inside without any reason.


If you need more info or help, let me know and I can maybe assist you (in case someone is still using these products and having the issue).


Re: Fan noise for various ProLiant servers (ML110, ML150, ...)

I have the same problem with a ouple of 110g7 so I'd like to have more information about solution.

many thanks


New Member

Re: Fan noise for various ProLiant servers (ML110, ML150, ...)

I experienced this with the addition of a 9211-8i-IT HBA card. Is it possible to ramp down the fans?

Granted, this is a DL380 G6, but I am sure there is a similar solution for it.