Latitude 5420/7420/7520 CPU Throttling Issue on Linux

The problem with this argumentation is that Dell says that they ship hardware "configurations" and only those which are "designed" for Linux are supported. In reality it is the same hardware I think but on the law side they are correct. Also I cannot by the 7320 with Linux at all. I tried pro support and ended up with this and I have to admin that they are right from an operations perspective. Nevertheless they should solve this problem! Can't be that hard as the XPS work fine with the same CPU.

I did it, with the same results. What makes me wonder is that any process that seems more "memory intensive" throttles de CPU down. It's easier to throttle it by watching a video in Youtube then running a stress-test in s-tui.

I just did some testing with thermald 2.4.8 to see if the issue was fixed but there is only the initial improvement as mentioned before. Here is the raw data recorded using turbostat when running 'stress -c 8': https://pastebin.com/raw/iBGc4Jk3

and also some graphs:

as shown there is only the initial turbo boot and then the processor throttles to 10W at 1800MHz with small spikes every 15s or so. In Windows, with the same laptop, it settles at least at the rated PL1 of 28W.

Tried with thermald 2.4.8 (latest stable version). Same result. It seems to be taking a little longer to throttle, but it might be more of a feeling than anything else. And I can't make ThermalMonitor work in anyway.

Are you using the standard Ubuntu kernel version, and if so, what is that kernel version?

$ uname -a
Linux laptop 5.13.0-25-generic #26~20.04.1-Ubuntu SMP Fri Jan 7 16:27:40 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Standard kernel, and I've downloaded the thermald code from github, tag 2.4.8.

Running Dell Latitude 7420 with i7-1185G7 with OL 8 (based on RHEL 8). The way this issue surfaced for me is occasionally laptop would start freezing during normal workloads with Zoom being very difficult to work with. Firefox would become very choppy just not pleasant experience at all. This was particularly obvious when plugging laptop back into power after using it on battery. Restarts would sort of improve it.Yesterday I installed the latest BIOS 1.14 (released on 13th of Jan). Unsure if related as I haven't payed much attention before but now the CPU averages 2.5 GHz on typical workloads. When I run s-tui stress test or the stress tool, the CPU still gets throttled ~ 1800 MHz with occasional 400 MHz which is intriguing as without the stress tool it averages well above that.

I will keep monitoring it over the next few days to see if the chopping experience returns.

As a follow-up from the post above. Unfortunately that issue is still cropping up. Whenever there is a bit more load on the CPU it gets occasionally throttled back to 400 MHz which causes choppy behavior.

Model: 7320, i7-1185G7

BIOS: 1.14.1

Linux: Opensuse Tumbleweed 5.16.0-1-default, Also tested on Debian and Ubuntu

Issue on Windows: no

What did I do: Stress CPU with "stress-ng -c 8"

OOB: Don't understand the question but was always present, since day 1

Troubleshooting: Please see the following issues on Github, these are really important and will answer many technical questions and affected models:

- https://github.com/intel/thermal_daemon/issues/293

- https://github.com/intel/thermal_daemon/issues/334

- https://github.com/erpalma/throttled/issues/255

As far as I understand the complete Latitude XX20 series is affected and they should all be under warranty as the model is not that old.

Thanks for your efforts!

Latitude model

5420, on warranty until 28 AUG 2024.

BIOS version installed

Currently, latest available through fwupd - 1.15.1.

Version of Linux

Arch Linux, Kernel version 5.16.1, currently. But the issue was present on preinstalled Ubuntu too.

Is the issue also happening with Windows operating system?

No, everything is fine on Windows.

What were you doing when the issue happened?

Doing a demanding task for a couple of minutes, like playing a game or compiling code.

Is it OOB (out of box - first time running/setting operational system) issue?

Yep, was present OOB.

What troubleshooting have you done?

Installed thermald, which makes CPU frequency ceiling higher while throttling (1400 Mhz instead of 400), but doesn't fix the issue completely. Also, lots of tweaks from GitHub issues mentioned in previous answer, you really should read through those, there's lots of troubleshooting info there.

Latitude model
Dell Latitude 5420 i7-1165g7

BIOS version installed?
Bios version 1.14.1

Version of Linux?
os: Ubuntu 20.04
kernel: 5.13.0-27-generic

Is the issue also happening with Windows operating system?
No it does not happen on Windows.

What were you doing when the issue happened?
For me its primarily a problem when I do code compilation as I do software development.

Is it OOB (out of box - first time running/setting operational system) issue?
Yes, I've also tested a few other Latitude 5420 laptops my IT department had that where brand new and still had the same issue.

What troubleshooting have you done?
Same as those above me in this post, using thermald helps, but does not fix the issue.

Latitude model?

5420, core i5, 32GB of RAM, 1TB of NVMe.

BIOS version installed?

1.13.1

Version of Linux?

Ubuntu 20.04. Result of uname -a: Linux laptop 5.13.0-25-generic #26~20.04.1-Ubuntu SMP Fri Jan 7 16:27:40 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Is the issue also happening with Windows operating system?

I don't know, as I don't have windows installed. I've installed Ubuntu on day-1. Bought the laptop beacuse of it.

What were you doing when the issue happened?

Anything. Watching a video on Youtube, replying to this thread in Firefox or Chrome, compiling code, using pycharm, etc. It's way more clear and perceptive on Youtube and on a Google meet.

Is it OOB (out of box - first time running/setting operational system) issue?

Yes. It was kind of slow from day 1, but I began monitoring it 2 months after acquiring it. Monitoring with s-tui and troubleshooting started 2 months after I bought it. I have it for 6 months now.

What troubleshooting have you done?

- Reinstalling ubuntu;

- Updating thermald from 2.4.5 to 2.4.8 (latest version);

- Lifting the laptop to cool it's bottom better;

- Updating the BIOS a couple of times (I think it came originally with BIOS 1.10 or 1.11, I don't remember) - the updates were though Ubuntu official update;

- Switching from thermald to throttled; - this actually made things worse, the CPU was throttling to 400Mhz instead of 1400Mhz;

- Reinstalling Ubuntu again to restore the original thermald;

- Enabling and disabling Intel speedstep (if I remember the name correctly) in the BIOS;

- Running only with battery;

- Running only with AC power;

And I'm out of ideas now. Every time the CPU throttles, the temperature is low, like 50~55 degrees Celsius as you can see in the image below.

In theory this CPU could go up to 95 degrees.