SuperMicro & low-RPM fans

Discussion in 'Processors and Motherboards' started by altano, Nov 22, 2015.

  1. altano

    altano Active Member

    Joined:
    Sep 3, 2011
    Messages:
    135
    Likes Received:
    28
    Hey Everyone,

    So the internet is littered with people discussing the problem where SuperMicro boards will oscillate between running your fans at "full" and "optimal." The issue is that low-RPM fans trigger an alert and cause the board to go into FULL fan mode until it realizes temps are okay, and then it goes back to normal, which slows the fans below the limit again, over and over.

    I've read all the guides about using ipmitool to lower the sensor thresholds and I was able to do this (I recommend booting to PLD Linux Rescue Live CD over IPMI, which is tiny and comes with ipmitool) but that didn't seem to help. I was still seeing fan assertions in the event log and the speed oscillation. I then lowered the threshold all the way to 0 (for all 3 thresholds) and I'm still getting the issue.

    Has anyone successfully fixed their SuperMicro board to work with low-RPM fans, and if so, did you have to do anything else?
     
    #1
  2. Patrick

    Patrick Administrator
    Staff Member

    Joined:
    Dec 21, 2010
    Messages:
    11,576
    Likes Received:
    4,522
    #2
  3. FMA1394

    FMA1394 Active Member

    Joined:
    Jan 11, 2013
    Messages:
    616
    Likes Received:
    174
    If these are PWM fans, just get a PWM controller and hide it somewhere. Using resistors is the wrong way to go.
     
    #3
    Patrick likes this.
  4. altano

    altano Active Member

    Joined:
    Sep 3, 2011
    Messages:
    135
    Likes Received:
    28
    The problem with a resistor is that the fan can then only spin at one speed (full - whatever the resistance is). Right?

    As for a PWM controller (yes these are PWM fans), can you be more specific? What would control the speed if not the motherboard?
     
    #4
  5. FMA1394

    FMA1394 Active Member

    Joined:
    Jan 11, 2013
    Messages:
    616
    Likes Received:
    174
    A knob.
    Something like this. You'll have to make the solution yourself. ZALMAN FAN MATE 2 Controller, Panel - Newegg.com

    Like this,
    Suppose you have a 4pin fan. Ground, Hot, Speed Sense, PWM.
    What you need to do (for each fan) is have the ground, hot, speed sense going into the motherboard. split the ground off and have that go into a 4 pin connector with the PWM wire and hook that into the pwm controller. So,
    1. the power and speed sensing are provided/given to the motherboard
    2. the ground and pwm signal are provided by the zalman.

    By doing it like this, you don't burn up the PWM controller and create fire hazards AND you don't have to buy a fan controller for each fan.

    Get creative, and good luck.
     
    #5
  6. britinpdx

    britinpdx Active Member

    Joined:
    Feb 8, 2013
    Messages:
    348
    Likes Received:
    151
    Are changes made by using the ipmitool persistent ? I seem to remember from tinkering in the past that they weren't and a power cycle (or cold reboot of the BMC) lost the changes.

    What's your use case ? I presume you are looking for a quiet system ?

    I've always referred to the Supermicro Fan Matrix for guidance when it comes to choosing a specific fan size for a specific use case.
     
    #6
  7. wbo

    wbo New Member

    Joined:
    Aug 4, 2015
    Messages:
    8
    Likes Received:
    2
    Another option (although a bit more expensive) is to use a fan controller that is capable of handling high-wattage fans, such as the Aquaero 6 which has 4 PWM channels that can handle up to 30W each. The version I put in my SC846 is at http://shop.aquacomputer.de/product_info.php?products_id=3092

    I put the front 3 fans each on their own channel and put the rear fans together on the 4th channel. The LCD panel is removable, so I took it off and mounted the fan controller inside the case and connected it to an internal USB header.

    The software included with the controller lets me set a custom fan curve for each channel based on temperatures from the thermal probes connected to the Aquero or based on temperatures reported by hard drives and the CPU. It is a bit expensive but very customizable and with it, the case is nearly silent when idling with SQ PSUs installed.
     
    #7
  8. fagiano

    fagiano Member

    Joined:
    Feb 5, 2011
    Messages:
    43
    Likes Received:
    7
    A quick and dirty solution is to disconnect the PWM wire, the fan will spin at full speed then use a "low noise adapter"(aka a resistor) to slow down the fan to a reasonable speed. You loose speed control, I personally can live with that.

    OT: I've been thinking to build a gizmo that multiplies the tachometer signal to fool the motherboard when using slow fans (but retaining speed control), It would require just a 2$ or 3$ worth of components... as soon as I have some spare time :D .

    Alberto
     
    #8
  9. Marsh

    Marsh Moderator

    Joined:
    May 12, 2013
    Messages:
    2,117
    Likes Received:
    964
    @fagiano
    There is a easier way for the quick and dirty solution
    Get one of this cable
    Gelid 1-to-4 Splitter CA-PWM-03 PWM (4Pin Molex/4Pin PWM to 4 x PWM Header)

    Re-pin the molex power cable from 12v to 5v. Plug in pwm sensor wire to the systemboard.
    All 4 fans are running at 5v, even at full speed, much quieter and descent airflow.

    I have many chassis, this is the cheapest way to accomplish the quick and dirty method.
    Do not use resistor, the systemboard would just ramp up the fan , causing the resistor to overheat.
     
    #9
    pgh5278 likes this.
  10. zeynel

    zeynel Active Member

    Joined:
    Nov 4, 2015
    Messages:
    463
    Likes Received:
    93
    @Marsh

    thx for the solution , great . ordered some from UK. will give feedback
     
    #10
  11. PigLover

    PigLover Moderator

    Joined:
    Jan 26, 2011
    Messages:
    2,776
    Likes Received:
    1,116
    I've had trouble with SM fans not starting on 5v. Even 7v is spotty (running them between the 12v and 5v line on the Molex). YMMV.

    Also - be cautious with resistor cables. Most of them are built for consumer fans that draw <1w run running full speed. SM fans can run 20-30w and will burn up the small resisters used on most of these cables.
     
    #11
  12. Lost-Benji

    Lost-Benji Member

    Joined:
    Jan 21, 2013
    Messages:
    368
    Likes Received:
    18
    NOOOOOOOOOO, PWM fans need full 12V rail all the time, the forth pin sends the pulse width to the controller in the fan motor to set speed/power of fan.

    A pulse doubler is the correct way to tell system that fan is turning twice as fast. Not easy to find or implement.

    Easier to get better fans and set the BIOS fan profiles.
     
    #12
    FMA1394 likes this.
  13. Lost-Benji

    Lost-Benji Member

    Joined:
    Jan 21, 2013
    Messages:
    368
    Likes Received:
    18
    SM boards are designed for 4-pin PWM fans but still work with 3-pin fans.
    3-pin fans can be/are controlled by limiting voltage to the fan, not 4-pin fans.
     
    #13
  14. Marsh

    Marsh Moderator

    Joined:
    May 12, 2013
    Messages:
    2,117
    Likes Received:
    964
    I waited until fagaino looking for a quick and dirty solution, running fan at 5volt is not ideal or proper solution.
    It only cost $10 bucks ( $6 each when buying 10 pieces, I brought 10 pieces), worth a shot.

    I used the above cable in Supermicro chassis with 4 pin fans. It keeps 16 drives running cool.

    I have few chassis, $50 for fan controller per chassis adds $$ up quick.
     
    #14
  15. FMA1394

    FMA1394 Active Member

    Joined:
    Jan 11, 2013
    Messages:
    616
    Likes Received:
    174
    Agreed. Marsh, please don't tell people to do that.
     
    #15
  16. pLu

    pLu New Member

    Joined:
    Nov 25, 2015
    Messages:
    19
    Likes Received:
    4
    I've built a Supermicro Avoton NAS with two Noctua NF-A9 PWM and one Noctua NF-A14 PWM. Also had the fan problem but configured the RPM thresholds according to the fan specs like this:

    ipmitool -I lanplus -H nas-sol -U ADMIN -P ADMIN sensor thresh FAN1 lower 300 300 400
    ipmitool -I lanplus -H nas-sol -U ADMIN -P ADMIN sensor thresh FAN2 lower 300 300 400
    ipmitool -I lanplus -H nas-sol -U ADMIN -P ADMIN sensor thresh FAN3 lower 200 200 300

    Problem solved.
     
    #16
    Last edited: Nov 25, 2015
    zivan56 likes this.
  17. pLu

    pLu New Member

    Joined:
    Nov 25, 2015
    Messages:
    19
    Likes Received:
    4
    The changes are persistent, like all other settings like network and users. I guess there's a risk losing them when upgrading the IPMI firmware.
     
    #17
  18. TType85

    TType85 Active Member

    Joined:
    Dec 22, 2014
    Messages:
    594
    Likes Received:
    167
    Thanks for this. It fixed my problems I had getting my Norco 4220 to be quiet.

    I put in the Noctua PWM 120mm industrial fans in the middle, 2 Noctua PWM 80mm in the back along with Noctua HSF's to cool a pair of 2620's. The fans would ramp when the board saw them to low. Now it's nice and quiet and my wife can't complain :)
     
    #18
  19. Stereodude

    Stereodude Active Member

    Joined:
    Feb 21, 2016
    Messages:
    398
    Likes Received:
    61
    Will this work on my Supermicro X9SRA? It doesn't have a BMC. I haven't gotten an OS installed on the system yet (still testing RAM and other stuff), so I can't try it. My fans are all 140mm (CPU fan included) and don't need to spin fast.
     
    #19
    Last edited: Mar 12, 2016
  20. pLu

    pLu New Member

    Joined:
    Nov 25, 2015
    Messages:
    19
    Likes Received:
    4
    No, those are BMC settings. Look for fan settings in BIOS instead.
     
    #20
Similar Threads: SuperMicro low-RPM
Forum Title Date
Processors and Motherboards IPMI IKVM + External display on Supermicro X11SBA-F? Today at 4:24 AM
Processors and Motherboards Noisy Supermicro Xeon D 5018D-FN4T Today at 2:29 AM
Processors and Motherboards Home Server based on Supermicro AS-E301-9D-8CN4 Thursday at 7:28 AM
Processors and Motherboards Supermicro H11SSL-NC Rev 2 - Flash onboard SAS3008 to IT Mode? Wednesday at 5:12 AM
Processors and Motherboards QL2K CPUs and Supermicro X11DPH Dec 1, 2019

Share This Page