Fans blasting from almost any activity, normal on xen?

User Support
1

I recently purchased a brand new Thinkpad T490 with i5-8265u (1.6 - 3.9 Ghz), 40GB ram + 1TB NVME however the fan noise is driving me bonkers.

Using the ‘sensor’ app I can see fan at 0rpm with no input for a few mins but as soon as I open a random browser tab and refresh it ramps up to 3500rpm and stays there for about a minute if no further input. If I’m just casually browsing it sticks at 3500-4100rpm.

xentop looks how I would expect. I have 8 AppVM’s and 8 sys-VM’s running. 90% of VM’s are idling at any point in time. But I have also tested with no AppVM’s running after a restart and can reproduce the same fan noise with just some basic activity in dom0 e.g. Using Qube manager. I even notice the fans ramping up when accessing the GUI version of the UEFI setup utility (f1 on startup).

Kernel = 5.11.8-1.fc25.qubes.x64
Laptop bios = 1.73
Hyperthreading = enabled but also tested with disabled
Ambient temperature = 20c (68f).

I have an LG 4k external monitor attached but tested without monitor, same results.

I have also tried:

sudo xenpm set-scaling-maxfreq 0 1600
sudo xenpm set-scaling-maxfreq 2 1600
sudo xenpm disable-turbo-mode 0
sudo xenpm disable-turbo-mode 2

But I don’t notice any difference. I imagine many qubes users using machines with less resources so I just want to understand if this is normal/expected behavior and whether there is anything else I can do about it. Or do I need to purchase a desktop for silence?

Thank you.

2

I strongly suspect this is due to lack of Intel p-state support in upstream Xen. I have a very similar problem on a Dell Latitude 7400 (2019), with an i5-8365

If you have some technical knowledge of Qubes or are willing to try to acquire it, you should try the following: Install the R4.1 Alpha, and then rebuild Xen with this patchset: https://github.com/QubesOS/qubes-issues/issues/4604#issuecomment-793077574. That patchset is against Xen head, here’s a version of the patchset against Xen 4.14 in Qubes R4.1 as of a few months ago: Add xen pstate patch · dmoerner/qubes-vmm-xen@4e91db0 · GitHub

3

Thank you @dmoerner ! That does look promising, I will attempt to patch my build. But does that not mean that all users with a mobile Intel processor (majority Qubes users) are affected by this issue? If so, is it just that most people don’t care or notice enough to complain? My employer sponsors my hardware, there is no amount I wouldn’t pay to get a cool and relatively quiet machine.

Can anyone else confirm whether they can use Qubes without fan blasting when doing almost anything and if so what hardware they are using?

4

It would affect users with a newer Intel processor. For example, I don’t run into it on my main machine, a T460. I admit I’m also a bit confused by this, I don’t understand how this isn’t a bigger issue for more people, since the heat also hurts the battery. But my newer computer, the Latitude 7400, does have notoriously bad thermal management anyway, so I imagined it might be better for other people. The p-state patches do work for me on the 7400 (although that computer still doesn’t suspend with Xen 4.14).