SuperMicro & low-RPM fans

Stereodude

Active Member
Feb 21, 2016
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So, Supermicro sent me a beta BIOS to test. It doesn't pump at 700RPM. It requires a drop below 300RPM to go full throttle. Unfortunately, the fan on my CPU, a Thermalright TY-147A, runs around 300-320RPM at idle, and will intermittently drop below 300RPM. :mad:

The Standard fan setting in the BIOS doesn't behave any differently than Optimal either. It should run the fans faster per the manual, but the PWM duty is exactly the same with either setting.

I have a few Thermalright TY-147A fans between my various computers on their heatsinks so I will see if I have one that runs a little faster with the same PWM input. Otherwise I'm going to get a small DC/DC step up regulator and increase the voltage to the fan slightly. Just enough to up the RPMs by a few so it stays clear of 300RPM.
 
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Stereodude

Active Member
Feb 21, 2016
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My other TY-147A ran even slower. I thought I had two more TY-147A fans, but they turned out to be TY-140 fans, which are very similar, but don't have as much RPM adjustment from PWM and they have a different bearing type. The first one I tested spins around 565RPM instead of the 300 of the TY-147A, so I put it on the CPU's heatsink and am now going to leave it alone. With the case all buttoned up after 30 minutes of Prime95 small FFT the CPU's hottest core was 52C. I haven't even put decent thermal compound on the thing yet. :eek:
 

IamSpartacus

Well-Known Member
Mar 14, 2016
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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.
Can someone comment on what the 300 300 400 numbers refer to? The reason I ask is that when I look at the fan sensor thresholds on my board (X10SDV-7TP4F) it shows me 4 values not 3. They are Low NR, Low CT, High CT, High NR.
 
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IamSpartacus

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Mar 14, 2016
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They're Lower Non-Recoverable (Low NR), Lower Critical (Low CT), Lower Non-Critical (Low NC).
Thanks @pLu. I wound up just setting them to 200 200 300. My board doesn't seem to have a Low NC but it took the command anyway and appears to be working.
 

Fritz

Well-Known Member
Apr 6, 2015
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I just bought an old SM 815 chassis with a X7DWU MB. The BIOS has fan speed settings for both 3 wire and 4 wire fans and it does indeed throttle the 3 wire fans as if they were 4 wire. Why did SM remove this feature from newer boards?
 

T_Minus

Build. Break. Fix. Repeat
Feb 15, 2015
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I have a question regarding the new thresholds.

I ran:
ipmiutil sensor -N 192.168.1.7 -U *-P * -n 42 -l 600

And it stopped the surging, and set the 'High' to "FF".

My questions:
What should I set high too? (during the surge it was up to 2300rpm)
What does FF mean?

Since these are just thresholds is there a command to set the minimum RPM for that fan to say 900RPM?
 

altano

Active Member
Sep 3, 2011
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Cambridge, MA
Sorry to dredge up an old thread but a lot of people had trouble setting up IPMITool and I thought I'd post a neat trick to do this super easily.

I had to lower the fan thresholds on a new machine and I didn't want to fiddle with putting Ubuntu on a USB key, booting to it, and getting IPMITool to run natively, but my main workstation is running Windows so I can't easily execute IPMITool commands remotely against the server's BMC. I've become familiar with Docker and I thought I would see how easy it would be to put up an Ubuntu Docker container and execute the IPMITool commands from there. It was trivial and took me just a couple of minutes. Here's how you would do it:
  1. From your Windows machine (or Mac) where you have Docker installed:
    1. Code:
      docker run --rm -it ubuntu bash
  2. Once inside your Ubuntu bash shell, run:
    1. Code:
      apt-get update
      apt-get install -y ipmitool
      ipmitool -H "<IPMI IP>" -U "<IPMI USERNAME>"-P "<IPMI PW>" sensor
    2. That will dump all your sensor settings including the fans and their current thresholds. Note down the names of all the fans you want to change and then change their thresholds. For me this was:
    3. Code:
      ipmitool -H "192.168.1.81" -U ADMIN -P "..." sensor thresh FAN1 lower 100 150 200
      ipmitool -H "192.168.1.81" -U ADMIN -P "..." sensor thresh FAN2 lower 100 150 200
      ipmitool -H "192.168.1.81" -U ADMIN -P "..." sensor thresh FANA lower 100 150 200
Since IPMITool is just executing commands against your BMC you don't have to futz with modprobe or anything. It doesn't even need sudo elevation.
 

cement_head

New Member
Nov 29, 2019
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Oxford, Ohio
openwetware.org
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.
Maybe an old thread, but yes, I believe this is the solution. For example a Phanteks PWM Hub Controller uses the SATA 12V connection to the PSU as the power source, and then connects a 4-pin PWM header to the motherboard to receive the PWM signal. Then case fans are connected to the fan controller hub and are accordingly increased and decreased in speed as instructed by the PWM header from the motherboard that is responding to thermal/temperature of the environment (usually the motherboard temp). However, the important aspect is that motherboard PWM fan header is not being used to power the fans, but merely to instruct the the fan controller to spin up and spin down the fans.

My question is what speed is being reported back to the motherboard, OR is it that no speed (or rather no feedback is being passed back to the motherboard), such that the SuperMicro motherboard is not going into an alarm (low speed; below 500 RPM) state?
 

cement_head

New Member
Nov 29, 2019
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Oxford, Ohio
openwetware.org
Thank you sir. I've quit for the day and am now chillin' with a beer. Will give it a try in the morning.

I did hook up a fan controller just to see if it would work and it does. I put 2 humongous Scythe fans in it and can control the speed from silent to wind noise, not too loud but can be heard. And no more oscillating between low and full blast. The reason for all this is because my CPU temps are on the high side, upper 50's at idle. I've got a pair of SM active coolers on the way. Seems these Dynatrons just can't cut it. Right now one is a 42 and the other is at 50. That's with the 2 Scythe's barely audible. Temps drop even more when I crank them up. I'd rather have the MB control the fan speed but I'll settle for what I have if need be. The dynatrons are very quiet, can barely hear them when the room is quiet, but they just don't cool very well. The 2 Scythe's are awesome fans, they push a tremendous amount of air and do so as quietly as it gets. Highly recommend them.
Which fan controller did you install? TIA
 

cement_head

New Member
Nov 29, 2019
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Oxford, Ohio
openwetware.org
I have found a solution/workaround. I am using a Phanteks PWM-PH fan controller hub: Phanteks Innovative Computer Hardware Design
  • Plug your CPU fans into the motherboard
  • Install the Phanteks PWM-PH hub (SATA power; PWM fan header for incoming (mobo -> fan controller) signal
  • Hook up your PWM fans to the fan controller, with ONE important expception
  • DO NOT connect the FAN1 output (the white connection) from the Phanteks PWM-PH to a fan - leave that empty
You should now have a fan controller hub that attenuates the PWM fans without feeding back the "low speed" back to the motherboard causing the SM board to alarm.
 
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