ASRock Forums : b450m mobo fan control does not work https://forum.asrock.com/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Tue, 21 Apr 2026 06:54:09 +0000 Tue, 27 Nov 2018 14:32:23 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.04 360 https://forum.asrock.com/RSS_post_feed.asp?TID=9699 <![CDATA[ASRock Forums]]> https://forum.asrock.com/forum_images/web_wiz_forums_black.png https://forum.asrock.com/ <![CDATA[b450m mobo fan control does not work : The &#034;monitor CPU&#034; temperature...]]> https://forum.asrock.com/forum_posts.asp?TID=9699&PID=58239&title=b450m-mobo-fan-control-does-not-work#58239 Author: kschendel
Subject: 9699
Posted: 27 Nov 2018 at 2:32pm

The "monitor CPU" temperature in the BIOS is supposed to be a motherboard thermistor that follows the CPU temp, but outside the CPU package. In effect it's an external CPU temperature rather than an on-die temperature. The advantage of such a thing is that it better reflects the temps that the CPU cooler "sees" and would therefore adjust the fan according to what the cooler heatsink needs as opposed to the die temperature, which fluctuates much more quickly.

Tctrl is a jiggered on-die, inside-the-package temperature. Tdie is the true die temp and Tctrl is Tdie+10C. (Why +10C? because someone at AMD thought it was a good idea.) Running a fan based on Tctrl will ramp the fan up and down more quickly and erratically because it's reflecting the inside the package temperature and not what's soaked into the heat sink.

Apparently this problem is widespread on Asrock boards, and it's seriously annoying. Why they have a sensor source that doesn't work and hasn't been removed or disabled, is beyond me.
]]> Tue, 27 Nov 2018 14:32:23 +0000 https://forum.asrock.com/forum_posts.asp?TID=9699&PID=58239&title=b450m-mobo-fan-control-does-not-work#58239 <![CDATA[b450m mobo fan control does not work : I just got a new Fatal1ty B450...]]> https://forum.asrock.com/forum_posts.asp?TID=9699&PID=58184&title=b450m-mobo-fan-control-does-not-work#58184 Author: DSD27
Subject: 9699
Posted: 25 Nov 2018 at 9:32pm

I just got a new Fatal1ty B450 Gaming K4 with the most recent bios and updates. Is this still the case?
What is tctrl and what is the difference from cpu?]]> Sun, 25 Nov 2018 21:32:10 +0000 https://forum.asrock.com/forum_posts.asp?TID=9699&PID=58184&title=b450m-mobo-fan-control-does-not-work#58184 <![CDATA[b450m mobo fan control does not work : It worked! Thank you! ]]> https://forum.asrock.com/forum_posts.asp?TID=9699&PID=56263&title=b450m-mobo-fan-control-does-not-work#56263 Author: Taxxi
Subject: 9699
Posted: 18 Sep 2018 at 7:31am

It worked! Thank you!
]]> Tue, 18 Sep 2018 07:31:54 +0000 https://forum.asrock.com/forum_posts.asp?TID=9699&PID=56263&title=b450m-mobo-fan-control-does-not-work#56263 <![CDATA[b450m mobo fan control does not work : datonyb wrote:set cpu fan monitoring...]]> https://forum.asrock.com/forum_posts.asp?TID=9699&PID=56222&title=b450m-mobo-fan-control-does-not-work#56222 Author: Taxxi
Subject: 9699
Posted: 16 Sep 2018 at 8:51pm

Originally posted by datonyb datonyb wrote:

set cpu fan monitoring to 'tctrl' in bios

Thank you sir, I think that might be the cause. I'll definitely try that after my old 2TB HDD successfully moves all the stuff to the new drive... BTW the fans can target the mobo temps just fine, am I correct?


Edited by Taxxi - 16 Sep 2018 at 8:51pm]]> Sun, 16 Sep 2018 20:51:04 +0000 https://forum.asrock.com/forum_posts.asp?TID=9699&PID=56222&title=b450m-mobo-fan-control-does-not-work#56222 <![CDATA[b450m mobo fan control does not work : set cpu fan monitoring to &#039;tctrl&#039;...]]> https://forum.asrock.com/forum_posts.asp?TID=9699&PID=56219&title=b450m-mobo-fan-control-does-not-work#56219 Author: datonyb
Subject: 9699
Posted: 16 Sep 2018 at 8:08pm

set cpu fan monitoring to 'tctrl' in bios
]]> Sun, 16 Sep 2018 20:08:55 +0000 https://forum.asrock.com/forum_posts.asp?TID=9699&PID=56219&title=b450m-mobo-fan-control-does-not-work#56219 <![CDATA[b450m mobo fan control does not work : I&#039;ve built my first build...]]> https://forum.asrock.com/forum_posts.asp?TID=9699&PID=56208&title=b450m-mobo-fan-control-does-not-work#56208 Author: Taxxi
Subject: 9699
Posted: 16 Sep 2018 at 11:26am

I've built my first build with Ryzen 2600X + ASRock B450M Pro4 mobo, and I found out that the cooler & fan speed wasn't following the prescribed value at the UEFI. So here are some tests I've done:


  1. CPU cooler 65% at 50C, 80% at 57C, 90% at 63C, and 100% at 70C, but when testing with OCCT and RealBench, the fan speed doesn't bump up until the CPU temp reaches 82~83C, and it is not even 100% it starts with 80%.

  2. Now if I put 100% at 50C, the CPU fan starts running crazy so I guess the controlling system works at least with the first phase.

  3. I thought the fan controlling system was lagging so I put the CPU temp near 60~70C using RealBench benchmark, but the cooler just remains silent, no speed bumping whatsoever.


So I guess either the HWMonitor is reading a wrong temp or the fan control system is not working, but I think the temp is right (32~34C at idle, -100mv vcore offset). This is really annoying. I tried A-tuning but it didn't work either. I'm using the latest BIOS (ver 1.2).


Any idea or solution would be appreciated. Thanks in advance :)


]]> Sun, 16 Sep 2018 11:26:26 +0000 https://forum.asrock.com/forum_posts.asp?TID=9699&PID=56208&title=b450m-mobo-fan-control-does-not-work#56208