Fan speed issue on Supermicro H8DG6-F

[saad moosajee]

Hi everyone,
I was gifted a Supermicro H8DG6-F with dual core g34 AMD Opterons cores by a friend to create a rendering computer. I'm very much an amateur with anything server related, but have been determined to get the PC build to work.

However, after numerous trials I've been unable to resolve my issue. My MB uses automatic fan control (only available for 4 pin fans) in combination with a BIOS setting (4 modes, performance, high, balanced, energy efficient) as a way of controlling fan speed. I work in a quiet co-working space and need the rendering PC to be reliably quiet. For cooling, I'm exclusively using Noctua 4 pin PWM for both my heatsinks and a few of the case fans. My computer at idle is incredibly quiet, which is wonderful.

However, any time I render anything (either GPU or CPU) my computer will stay nice and quiet, and then, out of no where, ramp up to sounding like its going to explode. I've downloaded a few tools to try and monitor fan speeds but unfortunately I'm not getting any readings (CAM, Openhardware) so all I can provide are guesswork RPM readings from my BIOS. I would say that at idle, my fans are spinning around 400 RPM ish, and when I render, they continue to hover around that range, until they all simultaneously ramp up to 1600 RPM at once and create a lot of noise.

The interesting part is that when they ramp up, its only for about 20 seconds, then they go back down to being perfectly quiet (while the render is still happening). Then, after another minute, they'll again ramp from being perfectly quiet to max RPM for 20 seconds, and go back down, in an endless loop until I cancel the render

Based on reading these forums, my understanding is that the BIOS thinks the fans are running too slowly because they fall below some RPM threshold so it hits them with 100% duty until the RPM recovers. The temperature control takes over again and the RPM falls based on the PWM sent to the fan and the process repeats.

I want to confirm that this is indeed the problem, and if it is, kindly ask that somebody might be able to provide a way of fixing the issue. I contacted Supermicro but they were not very responsive. They told me I could "use a third party ipmiutil tool if I desired" to fix it. I saw a couple of ipmiutil commands floating around the forums, but because I am very inexperienced in these matters, I was apprehensive about using one of the commands incorrectly and messing up my machine. I am using Windows 10 pro for OS

Sorry for rambling and thanks everyone for your time. Any help you could provide would be hugely appreciated!! I have been struggling with this issue for months.

 

[Terry Kennedy]

The interesting part is that when they ramp up, its only for about 20 seconds, then they go back down to being perfectly quiet (while the render is still happening). Then, after another minute, they'll again ramp from being perfectly quiet to max RPM for 20 seconds, and go back down, in an endless loop until I cancel the render

Based on reading these forums, my understanding is that the BIOS thinks the fans are running too slowly because they fall below some RPM threshold so it hits them with 100% duty until the RPM recovers. The temperature control takes over again and the RPM falls based on the PWM sent to the fan and the process

That sounds about right - full speed fans are not normal. You can use ipmitool or the IPMI web interface to find the particular thresholds for your board. For example, these are mine (from an X8DTH-iF):

Sensor name        Value        Type         Stat    Low Irr.    Low Crit    Low Warn    High Warn   High Crit   High Irr.
----------------   ----------   ----------   -----   ---------   --------    --------    ---------   ---------   ---------
Fan1             | na         | RPM        | na    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan2             | 3780.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan3             | 3780.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan4             | 3645.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan5             | 3645.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan6             | 3645.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan7             | 2700.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan8             | 2700.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000

From this, you can see anything under 675 RPM may trigger warnings, and things will definitely go full-speed below 405 RPM. You can either adjust the thresholds with ipmitool (if your board supports it - for example, not all Supermicro boards will accept requests to change the threshold) or select fans that operate at the speeds the motherboard expects. Note that when selecting generic fans, there are a huge number of options - for example, the fan speed signal can be ordered as 1 pulse per revolution, 2, etc. Companies that manufacture fans for a living (Nidec, San-Ace, for example) generally publish nice spec sheets with tables and graphs. The enthusiast / aftermarket fan business doesn't seem to provide anywhere near as much detail, which leaves end users experimenting.

Depending on what sorts of sounds you find annoying, you may also be unhappy with the fans making minor changes in speed. Here's a graph of fan speed in the same X8DTH-iF over the period of a week. This system is running in a room without active cooling during the winter months. Sunday was cold (low of 15° F), today is a lot warmer (60° F):

 

[saad moosajee]

That sounds about right - full speed fans are not normal. You can use ipmitool or the IPMI web interface to find the particular thresholds for your board. For example, these are mine (from an X8DTH-iF):

Sensor name        Value        Type         Stat    Low Irr.    Low Crit    Low Warn    High Warn   High Crit   High Irr.
----------------   ----------   ----------   -----   ---------   --------    --------    ---------   ---------   ---------
Fan1             | na         | RPM        | na    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan2             | 3780.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan3             | 3780.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan4             | 3645.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan5             | 3645.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan6             | 3645.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan7             | 2700.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000
Fan8             | 2700.000   | RPM        | ok    | 405.000   | 540.000   | 675.000   | 34155.000 | 34290.000 | 34425.000

From this, you can see anything under 675 RPM may trigger warnings, and things will definitely go full-speed below 405 RPM. You can either adjust the thresholds with ipmitool (if your board supports it - for example, not all Supermicro boards will accept requests to change the threshold) or select fans that operate at the speeds the motherboard expects. Note that when selecting generic fans, there are a huge number of options - for example, the fan speed signal can be ordered as 1 pulse per revolution, 2, etc. Companies that manufacture fans for a living (Nidec, San-Ace, for example) generally publish nice spec sheets with tables and graphs. The enthusiast / aftermarket fan business doesn't seem to provide anywhere near as much detail, which leaves end users experimenting.

Depending on what sorts of sounds you find annoying, you may also be unhappy with the fans making minor changes in speed. Here's a graph of fan speed in the same X8DTH-iF over the period of a week. This system is running in a room without active cooling during the winter months. Sunday was cold (low of 15° F), today is a lot warmer (60° F):

Thanks for the detailed response. Forgive my ignorance regarding the following few questions, as I mentioned earlier I am a complete amateur in this area.

1. Is this the IPMI tool you are referring to? ipmiutil - IPMI Management Utilities

2. I'm trying to get a sense roughly of what commands I would use to configure the threshold if my board supports it, ( trying to figure out where to look to find that..? checked on google search but nothing came up) I found this command on a similar thread, does this roughly look like what I would use in ipmitool? (assuming I might need to add some flags here to specify my board ..?) I am on a windows machine.

ipmitool sensor thresh FAN1 lower 300 300 400
ipmitool sensor thresh FAN2 lower 300 300 400
ipmitool sensor thresh FAN3 lower 200 200 300

Thank you so much and again, apologies for asking so many basic questions

 

[Terry Kennedy]

1. Is this the IPMI tool you are referring to? ipmiutil - IPMI Management Utilities

No, I meant IPMItool. I'm not sure how easy it would be to find a Windows executable, though.

2. I'm trying to get a sense roughly of what commands I would use to configure the threshold if my board supports it, ( trying to figure out where to look to find that..? checked on google search but nothing came up) I found this command on a similar thread, does this roughly look like what I would use in ipmitool? (assuming I might need to add some flags here to specify my board ..?) I am on a windows machine.

ipmitool sensor thresh FAN1 lower 300 300 400
ipmitool sensor thresh FAN2 lower 300 300 400
ipmitool sensor thresh FAN3 lower 200 200 300

It depends on what your board supports - sometimes you need to use ipmitool raw commands. In that case, you should obtain the exact commands for your board from Supermicro support - it is very easy to change something you don't want to if you just poke around.

Thank you so much and again, apologies for asking so many basic questions

No problem, we were all new once...