Arch Linux

UltraLux97

Member

Registered: 2022-06-03

Posts: 3

[SOLVED] Lenovo z50-70 with 4th gen i7 is unusually slow

Hello,

I am running Arch Linux with the latest KDE Plasma version on a Lenovo Ideapad z50-70 with an Intel Core i7-4510U @ 2.1000 GHz and 8 GB of RAM and Mesa Intel HD Graphics 4400. I've run Arch Linux on this machine for about 9 months now, changing DEs every now and then but usually using KDE Plasma. Before this, I had run KDE Plasma in 2020 on Kubuntu, EndeavourOS and Manjaro, and I have also run Windows 10 on this.

Ever since about December 2021, I've noticed that the machine has been incredibly slow. Compared to Windows it performs awfully off of an install following the Arch Wiki. On Windows I had 2 browsers (Ungoogled Chromium and Brave) open, each with their own Discord, YouTube and new-design Reddit tabs open and it'd perform fairly decently. On KDE, it can barely have 1 browser open with Discord and a YouTube of about 100 videos (YouTube is mostly in the background though and I do run an Audio Only Extension which in theory should reduce the resources used) - adding another browser to the mix is impossible, and new-design Reddit drags it to a crawl. Animations also have noticeable lag in spite of setting the compositor to force the smoothest animations possible, ensuring it used OpenGL for the rendering backend, etc.. It was never this slow on any other OS - Windows 10 or Kubuntu.

Running htop, I've noticed that the issue seems to be the CPU. The RAM usage is fine and doesn't tend to exceed 2 GB or so, the temperature generally hovers around 60-70 C checking from KDE's monitor, and turning on/off hardware acceleration for my browser (Ungoogled Chromium still) made only a small difference. Whenever I do an intensive task, such as switching Discord channels or clicking another video in my YouTube playlist or even just opening a new tab and searching something on either Google or DuckDuckGo, the CPU threads all spike to at least 70-80% and oftentimes 100%. When idling, the CPU usage is relatively low - no more than 10-15% and often less than 5%.

The CPU itself is mostly used by Ungoogled Chromium. In particular, the /usr/lib/chromium/chromium --type=renderer --display-capture-permissions-policy-allowed --change-stack-guard-on-fork=enable --lang=en-US --num-raster-threads=2 --enable-main-frame-before-activation --renderer-client-id=11 --launch-time-ticks=96546250 --shared-files=v8_context_snapshot_data:100 --field-trial-handle=0,i,8952165926558151528,8157417337735563184,131072 --enable-features=VaapiVideoDecoder process is what tends to use the most CPU. When I run chromium from the command line, it does say that [1380:1380:0603/221843.998184:ERROR:vaapi_wrapper.cc(791)] vaQueryConfigEntrypoints failed, VA error: the requested VAProfile is not supported which shows evne though I do enable the flag to override the software rendering list and chrome://gpu shows that video decode is hardware accelerated (though not encode, which is software only). ATM I do run 8 extensions - Audio Only Youtube, Chromium Web Store, Chromium Wheel Smooth Scroller, enhanced-264ify, Less-Addictive-Youtube, Plasma Integration, Proxy SwitchyOmega, and uBlock Origin. All of these are things I cannot do without except the enhanced-264ify which I only am using for the purpose of trying to optimize performance. This is about the number of extensions I'd run on other OSes (usually those ran 1-2 less though).

I've noticed that other DEs - most noticeably MATE and LXQt - don't slow down nearly as much as KDE does when these tasks are performed. That being said, the CPU still spikes quite a lot, and while it does perform acceptably with basic tasks it can't handle as much as the machine could when it ran Windows 10. Either way, I'd still much prefer KDE Plasma to these and would only use other DEs if I absolutely had to for various usability reasons.

In terms of performance optimizations, I've done the following:
- Turned the CPU mitigations off in GRUB. I'm aware of the dangers of doing this but I'm quite desparate. Performance improved noticeably when I did this - it was basically unusable before.
- Turned the CPU governor to performance. This did help a decent bit but not by much and I'd rather not have to rely on this.
- Switched graphics drivers - of which iHD surprisngly put up the best performance in spite of being the wrong driver and mpv --hwdec=auto not working which implies to me that hardware acceleration may be harming this and not helping. ATM I use i965 in spite of hybrid supposedly being the one for my machine, and I set the LIBVA_DRIVER_NAME env var to use it specifically in /etc/environment.
- Tried different kernels. linux-zen used less CPU but was slower in turn and performance was noticeably worse, and the unsupported linux-clear noticeably improved speed but not by enough to support the workloads that I'd want.
- Tried an extension to use different codecs in Chromium. There's frankly little difference, though VP8 seems to be the best overall.
- Tried an extension to prevent the video stream from loading in YouTube. This did not do much surprisingly.
- Tried Wayland, it made animations somewhat smoother but did nothing else.
- Tried changing the KDE Compositor settings to force the smoothest animations, which frankly did almost nothing. I also set it to prefer lower latency and that actually sped things up a little bit but again not by anything substantial.
- EDIT: I have also recently run profile-cleaner for Chromium for the first time since using the machine, which frankly did nothing in terms of performance.

At this point I'm convinced that either this machine just isn't up to the tasks I want to run, or from what I've heard asking in a few Discords that KDE Plasma is not properly optimized for this machine (which I'm not sure is the case seeing that MATE and LXQt still don't do great). Either way, this is quite bizarre considering that other Linux distros worked just fine without different kernels, mitigations off, etc. and Windows 10 worked well in spite of it generally being heavier, so I think it might be something else.

Please let me know what I can do to fix this performance, including posting any other system information I can get. Thank you very much!

Last edited by UltraLux97 (2022-06-06 17:49:32)

jonno2002

Member

Registered: 2016-11-21

Posts: 837

Re: [SOLVED] Lenovo z50-70 with 4th gen i7 is unusually slow

what happens if you use firefox (with or without webrender enabled)? any difference

UltraLux97

Member

Registered: 2022-06-03

Posts: 3

Re: [SOLVED] Lenovo z50-70 with 4th gen i7 is unusually slow

I did try Firefox (well, all of Firefox Librewolf and Firedragon) and before I could really do much there were major font display issues that I simply could not resolve in all 3 that I tried. Either way, I do have to use certain Google services rather heavily (YouTube and Gmail most noticeably) so I don't believe that Firefox-based browsers would be too viable. I'd be willing to try it out more if I could fix the font issues, but that's another issue for another thread

Also since the last post I've tried disabling zswap which has helped a bit, and I'm intending on trying ananicy and tuned. I'll update the OP with this information later.

UltraLux97

Member

Registered: 2022-06-03

Posts: 3

Re: [SOLVED] Lenovo z50-70 with 4th gen i7 is unusually slow

UPDATE: After not being able to figure anything out, I just decided to boot a live USB of another distro with KDE (Manjaro) and see how that performed in the live session. It performed a good amount better even without all the fancy configurations I did such as disabling mitigations or using another kernel, so it seemed pretty clear to me that I needed to reinstall. I ended up doing so and it's much more performant, especially _after_ re-enabling a lot of my configurations.

Marking this as solved.