[SOLVED] Lenovo IdeaPad Gaming 3-15IMH05 laptop overheating on AC but not on battery

generic_person · 03-11-2021, 02:14 PM

Hello,
I've recently bought a new Lenovo IdeaPad Gaming 3-15IMH05 laptop (with the intel i7-10750H CPU and Nvidia gtx 1650ti GPU). I use Debian 11 (Bullseye) with the KDE Plasma desktop environment. Everything seems to work well, but there is a problem: when I play games while on AC power, the CPU temps climb up to 98°C, but when I play the same games while on battery power, the CPU temps stay only around 70°C or less (the performance of the games doesn't really change).

I have TLP and thermald installed. According to the TLP config, the CPU scaling_governor is set to powersave both on AC and on Battery. The enegry_performance_preference was by default set to balance_performance on AC and balance_power on battery, so I tried to change it to balance_power on AC too, but it didn't help the overheating issue. I don't have any custom thermald settings so that should be the default.

If it helps, here's the logs from tlp-stat:
While on AC power:
https://pastebin.com/W4psurQH
While on battery:
https://pastebin.com/GzBGtjJg
(through pastebin, too long to fit into the post)

I'm not really sure what could be wrong here, so I'm not sure what more to try right now. I tried searching for this problem but I haven't found anything relevant yet. Thanks for any help, and just ask if you need any more information or logs.

computersavvy · 03-11-2021, 08:13 PM

It sounds like a cpu governor issue. On AC it appears to not engage the governor and on Bat it is engaged.

Alternatively it might be a fan issue, where the fan is not getting enough air flow for the higher CPU usage when on AC.

generic_person · 03-12-2021, 05:46 AM

Hello, thanks for the response.
The problem might very well be caused by the hardware if the cooling can't cool the CPU running on full power fast enough. But still, when on battery the CPU cools to acceptable temperatures, and I'd be willing to sacrifice performance for good temps.

Your suggestion about it being a CPU governor issue makes sense, but I'm not sure what to do with that, as I'm not that experienced with this. I tried changing the TLP config file to force battery power mode even when plugged in AC power, but the problem still persists, and I tried disabling thermald in case that messes with something, but that also didn't change anything.

I also tried looking around a bit more and found that the cpupower package (linux-cpupower in the Debian repositories) can monitor the CPU frequencies and governors, so I tried to install that to see what it says about the CPU governor currently in use, but the command "cpupower frequency-info" gives me the same output on AC and on battery (and says that the governor being used is powersave in both cases):

Code:

analyzing CPU 0:
  driver: intel_pstate
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency:  Cannot determine or is not supported.
  hardware limits: 800 MHz - 5.00 GHz
  available cpufreq governors: performance powersave
  current policy: frequency should be within 800 MHz and 5.00 GHz.
                  The governor "powersave" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 893 MHz (asserted by call to kernel)
  boost state support:
    Supported: yes
    Active: yes

I know that the CPU temps can drop to acceptable levels (they do when on battery), so all that I want is for the CPU to act the same on AC as it does on Battery, even if it means lower performance, but I'm not really sure how I should do that. Thanks for the help, any suggestions are appreciated, and ask if you need any more information or logs.

generic_person · 03-13-2021, 05:02 PM

After a bit of searching, I've found a strange thing. When I monitor the CPU frequency using the command "watch cpupower frequency-info" while playing a game, when on battery, the frequencies are much lower than on AC. When on battery, the CPU frequency is around 1-2 GHz, maybe around 3 GHz at most, but as soon as I plug the charger into the laptop, the frequency suddenly jumps to 4 GHz, no matter what game I'm playing. This suggests that it probably is a CPU governor issue, but everywhere I look (both the command "cpupower frequency-info" and the files "/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor"), it says that the governor being used is powersave, on battery and with AC.

I'm really not sure what this could be caused by and what more to try, so any suggestions are appreciated.

computersavvy · 03-14-2021, 10:45 AM

Quote:

Originally Posted by generic_person

After a bit of searching, I've found a strange thing. When I monitor the CPU frequency using the command "watch cpupower frequency-info" while playing a game, when on battery, the frequencies are much lower than on AC. When on battery, the CPU frequency is around 1-2 GHz, maybe around 3 GHz at most, but as soon as I plug the charger into the laptop, the frequency suddenly jumps to 4 GHz, no matter what game I'm playing. This suggests that it probably is a CPU governor issue, but everywhere I look (both the command "cpupower frequency-info" and the files "/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor"), it says that the governor being used is powersave, on battery and with AC.

I'm really not sure what this could be caused by and what more to try, so any suggestions are appreciated.

That makes perfect sense. On battery the system lowers the power demand to extend the battery life. On AC there is no concern about battery life so the cpu is able to run at max performance and apparently ignores the governor.

It seems the governor is not actually affecting the cpu speed when on AC so you may be able to adjust tlp to adjust the speed and limit the temp more. Also, disabling thermald may have the opposite affect to what you want. Thermald is designed to limit temps by reducing speed. If you can adjust its settings you might gain from it.

Temperature issues like this are why most gamers use desktops instead of laptops. My laptop shows a max temp (and critical temp) as 100C so if yours is running near there it seems likely to be damaging to the hardware.

The command "inxi -Cxx" will give you full detailed info about the CPU and its speed. If you have lm-sensors installed the command "sensors" will give you the current fan speeds and temps.

Another thing I know of that can severely impact cpu temp on a laptop is the buildup of a little dust/lint in the air flow path inside the machine. I had mine (intel i7-9750H 6 core 12 thread) running for an extended period (several weeks) at near 100% load and a very stable 60-65C temp. When it collected a little dust it very quickly began overheating and would shutdown on high temp at ~50% load in the same room temp. That might be worth investigating, as well as verifying fan speed.

generic_person · 03-14-2021, 11:33 AM

Thanks for the response, I think I managed to solve the problem.

Quote:

Originally Posted by computersavvy

It seems the governor is not actually affecting the cpu speed when on AC so you may be able to adjust tlp to adjust the speed and limit the temp more.

It makes sense that the overheating was caused by the CPU governor not affecting the speeds when on AC, so as you suggested I tried to limit the CPU speeds through the TLP settings, and that seems to work. Using the line

Code:

CPU_MAX_PERF_ON_AC=30

, I can limit the CPU clock speeds, in this case to 30% of maximum power. With this additional TLP configuration, the maximum CPU frequency is in fact lower, and so are the temperatures, now staying around 60-70°C.
Thanks for the help, I appreciate it.