Performance issues with newer kernels


First of all, if my post is in the wrong section I apologise

Recently I've experienced random lags with my system.
For example sometimes when I watch a video on youtube and then exit full screen my pc will lag for about 2-3 seconds.. both my mouse and keyboard will have trouble with
input, mouse becomes sluggish on moving, keyboard input will have a delay on commands such as alt-tab (sound is unaffected by the lag)
It not only happens in firefox/youtube I've had it happen in dolphin, dbeaver, virtualbox, chromium (pretty much anything)

I used to have a nvidia graphics card few months ago, sold it and removed the drivers.. maybe something was left behind that is causing this.. idk
Also tried what was posted in this thread: Kernel 5.x (5.4.6) slow/freezing during I/O operations it didn't help me

The only workaround is to use: 4.19 LTS kernel (system performs flawlessly with this one)
The newer LTS kernels.. not so much

Most of the time I have open Firefox with a few tabs (4-5 at most), a headless vm with less than 512 ram, deadbeef for music, keepass, telegram and a few terminals open

I really don't want to reformat (even tho I planned to partition my / properly.. and to try btrfs) I'm not in the mood for reformatting just yet.

Any help would be much appreciated.

P.S. inxi output

System:    Host: darkstar Kernel: 5.4.34-1-MANJARO x86_64 bits: 64 compiler: gcc v: 9.3.0 Desktop: KDE Plasma 5.18.4 
           tk: Qt 5.14.2 wm: kwin_x11 dm: SDDM Distro: Manjaro Linux 
Machine:   Type: Desktop System: ASUS product: All Series v: N/A serial:  
           Mobo: ASUSTeK model: SABERTOOTH Z97 MARK 2 v: Rev 1.xx serial:  UEFI: American Megatrends v: 3503 
           date: 04/18/2018 
Battery:   Device-1: hidpp_battery_0 model: Logitech MX Ergo Multi-Device Trackball serial:  
           charge: 55% (should be ignored) rechargeable: yes status: Discharging 
CPU:       Topology: Quad Core model: Intel Core i5-4690K bits: 64 type: MCP arch: Haswell rev: 3 L2 cache: 6144 KiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 28012 
           Speed: 1009 MHz min/max: 800/3900 MHz Core speeds (MHz): 1: 3466 2: 3403 3: 3482 4: 2591 
Graphics:  Device-1: Intel Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics vendor: ASUSTeK driver: i915 v: kernel 
           bus ID: 00:02.0 chip ID: 8086:0412 
           Display: x11 server: X.Org 1.20.8 driver: intel compositor: kwin_x11 resolution: 1920x1080~60Hz 
           OpenGL: renderer: Mesa DRI Intel HD Graphics 4600 (HSW GT2) v: 4.5 Mesa 20.0.4 compat-v: 3.0 direct render: Yes 
Audio:     Device-1: Intel Xeon E3-1200 v3/4th Gen Core Processor HD Audio vendor: ASUSTeK driver: snd_hda_intel v: kernel 
           bus ID: 00:03.0 chip ID: 8086:0c0c 
           Device-2: Samson GoMic compact condenser mic type: USB driver: hid-generic,snd-usb-audio,usbhid bus ID: 5-1:2 
           chip ID: 17a0:0305 
           Device-3: Yoyodyne Consulting ODAC-revB type: USB driver: hid-generic,snd-usb-audio,usbhid bus ID: 2-13:6 
           chip ID: 262a:1048 
           Sound Server: ALSA v: k5.4.34-1-MANJARO 
Network:   Device-1: Intel Ethernet I218-V vendor: ASUSTeK driver: e1000e v: 3.2.6-k port: f080 bus ID: 00:19.0 
           chip ID: 8086:15a1 
           IF: eno1 state: down mac:  
           Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet vendor: TP-LINK TG-3468 driver: r8168 
           v: 8.048.00-NAPI port: e000 bus ID: 05:00.0 chip ID: 10ec:8168 
           IF: enp5s0 state: up speed: 1000 Mbps duplex: full mac:  
           IF-ID-1: vboxnet0 state: down mac:  
Drives:    Local Storage: total: 3.41 TiB used: 2.15 TiB (63.0%) 
           ID-1: /dev/sda vendor: Crucial model: CT500MX500SSD1 size: 465.76 GiB speed: 6.0 Gb/s serial:  rev: 023 
           scheme: GPT 
           ID-2: /dev/sdb vendor: Western Digital model: WD7501AALS-00J7B0 size: 698.64 GiB speed: 3.0 Gb/s serial:  
           rev: 0K05 scheme: GPT 
           ID-3: /dev/sdc vendor: Seagate model: ST1000VN002-2EY102 size: 931.51 GiB speed: 6.0 Gb/s rotation: 5900 rpm 
           serial:  rev: SC60 
           ID-4: /dev/sdd vendor: Seagate model: ST1000VN002-2EY102 size: 931.51 GiB speed: 6.0 Gb/s rotation: 5900 rpm 
           serial:  rev: SC60 
           ID-5: /dev/sde vendor: Hitachi model: HTS725050A9A364 size: 465.76 GiB speed: 3.0 Gb/s rotation: 7200 rpm 
           serial:  rev: C72E scheme: GPT 
Partition: ID-1: / size: 448.50 GiB used: 212.09 GiB (47.3%) fs: ext4 dev: /dev/sda2 
           ID-2: swap-1 size: 8.80 GiB used: 384.8 MiB (4.3%) fs: swap dev: /dev/sda3 
Sensors:   System Temperatures: cpu: 29.8 C mobo: 27.8 C 
           Fan Speeds (RPM): N/A 
Info:      Processes: 207 Uptime: 23h 35m Memory: 7.47 GiB used: 3.69 GiB (49.4%) Init: systemd v: 244 Compilers: gcc: 9.3.0 
           Shell: zsh v: 5.8 running in: terminator inxi: 3.0.37 

run in a terminal

watch --interval=5 'free --human' 

post the output when it happens (you only have about 5 seconds to copy-paste the text...

My apologies if I intervene the comms (I see none responds and I do not want to create a new topic) , I have the same issue, sometimes, over the sudden system freezes and only HD runs non-stop; in some time it shuts screens to dark (no video output) and no way to reanimate system - only forced pwr off; and my output is:

Every 5.0s: free --human alex-pc: Sun Apr 26 16:55:26 2020

          total        used        free      shared  buff/cache   availab

Mem: 3.7Gi 1.4Gi 1.0Gi 169Mi 1.3Gi 1.9
Swap: 0B 0B 0B

Better open a new topic as your issue looks different.

Also please read this before you open your new topic :

as we need more information to pinpoint your specific issue


P.S. If you enter a bit more details in your profile, we can also see which Desktop Environment you're using, which CPU/GPU you have, ...

Most likely you have an older Intel CPU. For them it is clear that newer kernel will be slower. This is based on the fact that newer kernel ship with higher and stronger minigation settings for known hardware flaws. However there is a way to turn them off on your own risk.


Thank you for the response. HW for sure is the main reason for the trouble.
How the settings can be managed? It should be set of critical settings, I assume
Are, which should be on all times.
Are there any older versions that would work on resource limited HW?

You don't understand: there are critical flaws in the Intel and AMD CPUs that need mitigations and those slow down your system. You cannot do without those mitigations!

The only way of increase the speed again is to buy a newer CPU which doesn't have these flaws.


P.S. For more information Google for "Spectre CPU flaws" and "meltdown CPU flaws"

Thank you

1 Like

You can read that here:

Be aware that the kernel defaults are intended to be safe; you should not need to alter them.

However, if you disable the mitigations you can verify whether they are to blame for the loss in performance. Just make sure you enable them again afterwards.

Will do, when it happens

1 Like

So it happened 2 times, this is the only info showing in terminal
Not sure if it can relate, I was downloading a file in qbittorrent onto another drive (unsure if drive can worsen the performance of the system)

Every 5,0s: free --human                                                                                                                    darkstar: Mon Apr 27 21:07:37 2020

              total        used        free      shared  buff/cache   available
Mem:          7,5Gi       2,5Gi       106Mi       544Mi       4,9Gi       4,2Gi
Swap:         8,8Gi       213Mi       8,6Gi

Every 5,0s: free --human                                                                                                                    darkstar: Mon Apr 27 21:12:03 2020

              total        used        free      shared  buff/cache   available
Mem:          7,5Gi       2,5Gi       175Mi       622Mi       4,8Gi       4,1Gi
Swap:         8,8Gi       229Mi       8,6Gi

I thought it was swapping, but it isn't...

Out of ideas, your honour...


It was worth a shot, thanks :slight_smile:

1 Like

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.

Forum kindly sponsored by