Hi, I’m not sure if this is the best place to ask this but I’m kinda desperate. I have a Lenovo IdeaPad Slim 5i 9gen, the most important aspect of this laptop is the CPU, Intel Core Ultra 5 125h.
I’ve recently moved to Linux (Cachy and KDE Plasma to be more exact), everything is running fine however I’ve noticed this strange issue where sometimes the system becomes sluggish, what I mean is that moving the cursors feels like the system is slow (the best way to describe is that the mouse feels that it’s running at 30fps instead of 60fps), this also applies to general navigation mainly scrolling apps or moving windows.
What I’ve Tried:
Change power management tools, mainly TuneD since it has more control over the system but it hasn’t fixed the issue
Disable PSR in the i915 driver
Set EPP to performance
Disabled any power management (it seems to improve a little but it always comes back)
Change scheduler (I tried the most popular ones in Cachy, lavd, bpfland, cosmos, pandemonium) settings lavd or bpfland to performance/gaming seems to make it even more sluggish as if I was in powersave mode.
Disable intel_lpmd
Install and enable ThermalD
It’s infuriating since I know this laptop is powerful enough to be responsive (since I never had this type of symptom on Windows), I will say that raw performance seems to be fine.
One thing I’ve found online and might be the reason although I’m not certain is that this is related to the C State of the CPU? I also know this CPU is a hit or miss under Linux because of it’s weird architecture (4 performance cores, 8 efficient cores, 2 low-power efficient).
Ah, was just stabbing at the first thing that came to mind. Same behavior on and off battery?
Any suspect parts indicated in dmesg?
I thing you may have hit a good suspect with the c states - did you force the states off (higher ones) or set the governor to performance only? Old first gen Ryzen was a nightmare with c states , but would work fine with the lowest power states off and smacking the power governor.
I haven’t tried disabled the C States, settings the EPP to performance doesn’t make a different (on these newer intel CPUs it’s recommended to set the governor to powersave).
Ah another thing, running something like i3 resolves the issue, but I don’t think KDE Plasma is that heavy to cause responsiveness issues on a CPU like this…
I think I found the issue, I was ready to give up and move back to Windows until I got into the BIOS and saw that the cooling mode was in battery saving, I put it in intelligent cooling and the PC is much smoother now!
I guess, it’s not thermal throttle but it was limiting the CPU, that’s also why the laptop was so silent .
There is still issues which I did talk with CachyOS devs about and it seems that using the BORE scheduler improves quite a bit, there’s also problems with the GPU.
Meteor Lake uses the i915 kernel module which is much slower compared to Windows, and while you can load the new Xe driver which greatly improves performance and responsiveness, it’s not fully supported for Meteor Lake and I did have some issues mainly XWayland crashing (which would then crash KWin) when playing specific games and small freezes when playing videos every few minutes.
I’m still testing, currently went back to Windows and I’m hating it so far, it’s slower but performance does seem a bit better? It’s weird, in terms of CPU performance it’s about the same with Linux being a bit better (basing off of benchmarks), GPU however it’s much worse, although I don’t notice it in gaming with the Xe driver, what seems quite fascinating is power consumption, Windows somehow is better (I did debloat it quite a bit but I have a lot of stuff running), I was able to tweak a bit using Powertop tunables and TuneD, but the GPU seems to be using a bit more power on Linux (it’s not possible to read the power consumption on the Xe driver as far as I know).
I hope some people find my findings helpful! Thanks again for the help .
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