Hi,


I am using Acer Gateway NE56R laptop with Intel Pentium B960 processor.
I have Debian Testing installed with linux kernel 5.10 and grub2 as bootloader.


When I boot my system and reach grub screen, after a second or two on grub boot screen, the fan runs fast (seems like full speed). When I boot into linux, the fan slows down and I have seen that it never runs at full speed while I am using my system, even when system is loaded 100% on both core. Instead of running fan faster, my system scale down cpu frequency.


I do not see any power management option in system BIOS. So looks like no BIOS control is available.


Is there any control in linux where I can allow fan to run at full speed?


I have used fancontrol utility but it doesn't detect any sensors. Neither does lm_sensors detect any fan sensor. It doesn't report any fan speed.


Thanks.

This intrigued me, so I did a quick web search, but turned up nothing that seemed particularly convincing, other than a few instances of persons asking similar questions at other forums.

Assuming that everything is working properly and there's no dust build-up on the vents, my best guess is that it's likely because boot up is probably the busiest time for the computer's CPU. More resources are being used at boot then at any other time, as the kernel probes for devices and files and all the physical components are firing up. Unless you are doing something really CPU-intensive, such as editing video, normal usage does not approach the intensity of start-up.

Like I say, just my guess.

I always thought that the intensive blowing at start up had to do with ensuring it was clear of dust, but as suggested, with everything being initiated, there likely is extra heat to be dispersed, compared to normal useage; whatever, as long as it settles down, everything should remain OK.

I've had that from day 1 and never worried about it.

Early BIOS stuff is pretty dumb. When the box turns on, the BIOS has control and the fan runs full speed. As the system boots, the kernel takes over and the profile of speeds in the DSDT gets implemented once ACPI gets into the frame. The fan slows. Thereafter, window managers and ACPI argue over who is boss, and that's out of my depth. As a simple way out, I tell one of them to go and play in the traffic. I don't exactly like acpi, but I've learned a bit about it.

Thanks all for the inputs.

@frankbell, I also thought in similar lines first, then I loaded both of my cpu core with 100% load (by running number crunching program), and I observed that the fan doesn't run so fast as it was on boot time.

Further constantly running on 100% load doesn't increase fan speed further to it's max but reduces down the frequency.

@fatmac, actually I am trying to run fan at highest possible speed (which I guess is achieved only on boot) so that I can use my old laptop to it's full capacity and not let it go throttled down (as said above, cpu frequency reduces at sustained loads instead of increasing fan speed) .

@business_kid, I did some research and dug through logs, and I agree that it is similar phenomenon as you described.

So to avoid throttling, I removed intel_powerclamp module, changed x86_energy_perf_policy to 0.

I am seeing slight improvement as now my system seems to be throttling less, but still fan doesn't run at full speed and throttling still occurs. (Not completely gone).

Hi all,

I started this investigation because I was facing thermal throttling and fan wasn't running fast.

Recently I found out that my laptop is 7+ years old and has accumulated lot of dust in the vents. I cleaned up the vents and now laptop is facing no issue with thermal throttling. The fan is still running quieter but doing it's job pretty well.

Thanks all.

I am closing this now.

The speed of the fan is not the most important thing. CPU temperature is critical and as long as it stays below ~80C there should be no issues. It can run a little higher, but most are set to do a thermal shutdown at about 100C so the cooler the cpu remains the better.

It sounds like your cpu throttling is coming in at a lower temperature than the fan. So the fan thinks it's cool enough, but the cpu thinks it's too hot.

Fan thresholds may be set in the BIOS, or power manager. Maybe you shouldn't unload intel modules unless you know they are causing issues.