T490 HCL / power consumption after suspend

[Andrew Sorensen]

I didn't see any reports of Qubes on the T490, so I figured I'd start one: I just got a T490 (i7 model with 32GB of ram), and was able to get Qubes 4.0.2rc1 installed and usable (after excluding the network card from FLR). For the most part, it appears it will be as usable as Qubes on my T470 with one problem: power consumption. On a cold boot, everything seems acceptable and I get a good number of hours of battery life, however after suspending the laptop and resuming, power consumption spikes from 4W to 15W+, reducing battery life down to a few hours and keeping the fan pegged.

I've tried upgrading to kernel-latest (e.g. 5.x) and using tlp/powertop/xenpm to troubleshoot further, but nothing stuck out. I also downloaded Fedora 30 and was able to suspend and resume without seeing the additional power increase. My understanding is that power management is handled by Xen, and not Dom0 so I think I'm pretty much out of options, but figured I'd drop a note in case anyone else runs into this. I don't plan to investigate much further since I also have the T470, but look forward to trying again when Qubes 4.1 is available in some form.

Also - if someone else wants to test/play around - make sure to use the latest qubes release. I first tried with the version I used to setup my T470 since I didn't have a lot of time, but there were graphical issues (*very* slow painting of the installer/desktop UI), and wireless and wired networking were unavailable.

[andrew...@gmail.com]

Ok, this wasn't expected but I actually see similar behavior on my T470 - power consumption is roughly 2X on the T470 after suspend/resume, and 3-4x on the T490. Can someone else try measuring power consumption before and after the first suspend/resume cycle and report back? I have a feeling this could be impacting more people.

[Andrew Sorensen]

It appears this a result of hyperthreading being enabled, see conversation in https://github.com/QubesOS/qubes-issues/issues/5210