Unfortunately, PaleMoon does not perform well under CPU load

[daveb]

I'm using the latest PaleMoon on my custom Linux distro. Unfortunately, performance of this browser is very poor compared to Chromium or WebKit. The main problem is long (3-5+ second) pauses, especially when there's any kind of background disk or CPU activity. Otherwise it's great, and is a nice blast from the past. I'd love to use it more if/when the threading model is improved. Thanks for your work on PaleMoon.

[jobbautista9]

Please follow the included template instead of completely ignoring it. There's nothing that can't be done for you here without troubleshooting information

[Night Wing]

@ daveb

You gave no information about what linux distro you customized, no desktop environment, no system specifications for your computer (no processor, no processor speed, no amount of memory, memory used, CPU temperature, etc).

But since you did mention high CPU usage, I can give you one example from one of my YouTube longboard surfing videos running at 2160p60 4K high definition mode which is using 64 bit linux (GTK2) Pale Moon 34.0.1 running in 64 bit MX Linux 25.1 (Infinity) Xfce. You can see the CPU usage in my System Monitor.

I have hardware acceleration enabled and I also have uBlock Origin 1.16.6.1 enabled for YouTube as well. And I do not have any 3-5 second pauses. Basically, no pauses time wise. BTW, I am using a desktop tower computer.

https://www.youtube.com/watch?v=w7UPOvRuVek

But before I give you the graph of my System Monitor showing the CPU load, I will give you my system's specifications first so you can compare them with your own computer's specifications.

Code: Select all

System:
  Kernel: 6.12.69+deb13-amd64 arch: x86_64 bits: 64 compiler: gcc v: 14.2.0 clocksource: tsc
    avail: hpet,acpi_pm parameters: BOOT_IMAGE=/boot/vmlinuz-6.12.69+deb13-amd64 root=UUID=<filter>
    ro quiet splash
  Desktop: Xfce v: 4.20.1 tk: Gtk v: 3.24.48 wm: xfwm4 v: 4.20.0 with: xfce4-panel tools:
    avail: xfce4-screensaver vt: 7 dm: LightDM v: 1.32.0 Distro: MX-25.1_x64 Infinity Nov 9 2025
    base: Debian GNU/Linux 13 (trixie)
Machine:
  Type: Desktop Mobo: Micro-Star model: MAG B660M MORTAR WIFI DDR4 (MS-7D42) v: 1.0
    serial: <superuser required> uuid: <superuser required> UEFI: American Megatrends LLC. v: 1.M0
    date: 04/17/2025
CPU:
  Info: model: 12th Gen Intel Core i7-12700K bits: 64 type: MST AMCP arch: Alder Lake gen: core 12
    level: v3 note: check built: 2021+ process: Intel 7 (10nm ESF) family: 6 model-id: 0x97 (151)
    stepping: 2 microcode: 0x3D
  Topology: cpus: 1x dies: 1 clusters: 9 cores: 12 threads: 20 mt: 8 tpc: 2 st: 4 smt: enabled
    cache: L1: 1024 KiB desc: d-4x32 KiB, 8x48 KiB; i-8x32 KiB, 4x64 KiB L2: 12 MiB
    desc: 8x1.2 MiB, 1x2 MiB L3: 25 MiB desc: 1x25 MiB
  Speed (MHz): avg: 800 min/max: 800/4900:5000:3800 scaling: driver: intel_pstate
    governor: powersave cores: 1: 800 2: 800 3: 800 4: 800 5: 800 6: 800 7: 800 8: 800 9: 800 10: 800
    11: 800 12: 800 13: 800 14: 800 15: 800 16: 800 17: 800 18: 800 19: 800 20: 800
    bogomips: 144383
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
  Vulnerabilities:
  Type: gather_data_sampling status: Not affected
  Type: indirect_target_selection status: Not affected
  Type: itlb_multihit status: Not affected
  Type: l1tf status: Not affected
  Type: mds status: Not affected
  Type: meltdown status: Not affected
  Type: mmio_stale_data status: Not affected
  Type: reg_file_data_sampling mitigation: Clear Register File
  Type: retbleed status: Not affected
  Type: spec_rstack_overflow status: Not affected
  Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via prctl
  Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer sanitization
  Type: spectre_v2 mitigation: Enhanced / Automatic IBRS; IBPB: conditional; PBRSB-eIBRS: SW
    sequence; BHI: BHI_DIS_S
  Type: srbds status: Not affected
  Type: tsa status: Not affected
  Type: tsx_async_abort status: Not affected
  Type: vmscape mitigation: IBPB before exit to userspace
Graphics:
  Device-1: Intel AlderLake-S GT1 vendor: Micro-Star MSI driver: i915 v: kernel alternate: xe
    arch: Xe process: Intel 10nm built: 2020-21 ports: active: none empty: DP-1, DP-2, HDMI-A-1,
    HDMI-A-2, HDMI-A-3, HDMI-A-4 bus-ID: 00:02.0 chip-ID: 8086:4680 class-ID: 0380
  Device-2: Advanced Micro Devices [AMD/ATI] Vega 10 XL/XT [Radeon RX 56/64]
    vendor: Micro-Star MSI driver: amdgpu v: kernel arch: GCN-5 code: Vega process: GF 14nm
    built: 2017-20 pcie: gen: 3 speed: 8 GT/s lanes: 16 ports: active: HDMI-A-5
    empty: DP-3,DP-4,DP-5 bus-ID: 03:00.0 chip-ID: 1002:687f class-ID: 0300
  Display: x11 server: X.Org v: 21.1.16 compositor: xfwm4 v: 4.20.0 driver: X:
    loaded: amdgpu,modesetting unloaded: fbdev,vesa dri: radeonsi gpu: amdgpu display-ID: :0.0
    screens: 1
  Screen-1: 0 s-res: 1920x1080 s-dpi: 96 s-size: 509x286mm (20.04x11.26") s-diag: 584mm (22.99")
  Monitor-1: HDMI-A-5 mapped: HDMI-A-4 model: ViewSonic VX3276-FHD serial: <filter> built: 2022
    res: mode: 1920x1080 hz: 60 scale: 100% (1) dpi: 70 gamma: 1.2 size: 698x393mm (27.48x15.47")
    diag: 801mm (31.5") ratio: 16:9 modes: max: 1920x1080 min: 720x400
  API: EGL v: 1.5 hw: drv: intel iris drv: amd radeonsi platforms: device: 0 drv: radeonsi
    device: 1 drv: iris device: 2 drv: swrast gbm: drv: kms_swrast surfaceless: drv: radeonsi x11:
    drv: radeonsi inactive: wayland
  API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 25.0.7-2 glx-v: 1.4 direct-render: yes
    renderer: AMD Radeon RX Vega (radeonsi vega10 ACO DRM 3.61 6.12.69+deb13-amd64)
    device-ID: 1002:687f memory: 7.81 GiB unified: no
  API: Vulkan v: 1.4.309 layers: 3 device: 0 type: discrete-gpu name: AMD Radeon RX Vega (RADV
    VEGA10) driver: mesa radv v: 25.0.7-2 device-ID: 1002:687f surfaces: xcb,xlib device: 1
    type: integrated-gpu name: Intel UHD Graphics 770 (ADL-S GT1) driver: mesa intel v: 25.0.7-2
    device-ID: 8086:4680 surfaces: xcb,xlib device: 2 type: cpu name: llvmpipe (LLVM 19.1.7 256
    bits) driver: mesa llvmpipe v: 25.0.7-2 (LLVM 19.1.7) device-ID: 10005:0000 surfaces: xcb,xlib
  Info: Tools: api: eglinfo, glxinfo, vulkaninfo de: xfce4-display-settings x11: xdriinfo,
    xdpyinfo, xprop, xrandr
Audio:
  Device-1: Intel Alder Lake-S HD Audio vendor: Micro-Star MSI driver: snd_hda_intel v: kernel
    alternate: snd_soc_avs,snd_sof_pci_intel_tgl bus-ID: 00:1f.3 chip-ID: 8086:7ad0 class-ID: 0403
  Device-2: Advanced Micro Devices [AMD/ATI] Vega 10 HDMI Audio [Radeon 56/64]
    driver: snd_hda_intel v: kernel pcie: gen: 3 speed: 8 GT/s lanes: 16 bus-ID: 03:00.1
    chip-ID: 1002:aaf8 class-ID: 0403
  API: ALSA v: k6.12.69+deb13-amd64 status: kernel-api tools: alsactl,alsamixer,amixer
  Server-1: PipeWire v: 1.4.5 status: active with: 1: pipewire-pulse status: active
    2: wireplumber status: active 3: pipewire-alsa type: plugin 4: pw-jack type: plugin
    tools: pactl,pw-cat,pw-cli,wpctl
Network:
  Device-1: Intel Alder Lake-S PCH CNVi WiFi driver: iwlwifi v: kernel modules: wl bus-ID: 00:14.3
    chip-ID: 8086:7af0 class-ID: 0280
  IF: wlan0 state: down mac: <filter>
  Device-2: Realtek RTL8125 2.5GbE vendor: Micro-Star MSI driver: r8169 v: kernel pcie: gen: 2
    speed: 5 GT/s lanes: 1 port: 4000 bus-ID: 05:00.0 chip-ID: 10ec:8125 class-ID: 0200
  IF: eth0 state: up speed: 1000 Mbps duplex: full mac: <filter>
  Info: services: NetworkManager, nfsd, systemd-networkd, wpa_supplicant
Bluetooth:
  Device-1: Intel AX201 Bluetooth driver: btusb v: 0.8 type: USB rev: 2.0 speed: 12 Mb/s lanes: 1
    mode: 1.1 bus-ID: 1-14:11 chip-ID: 8087:0026 class-ID: e001
  Report: hciconfig ID: hci0 rfk-id: 1 state: up address: <filter> bt-v: 5.2 lmp-v: 11
    sub-v: 37c8 hci-v: 11 rev: 37c8 class-ID: 6c0104
  Info: acl-mtu: 1021:4 sco-mtu: 96:6 link-policy: rswitch sniff link-mode: peripheral accept
    service-classes: rendering, capturing, audio, telephony
Drives:
  Local Storage: total: 912.89 GiB used: 20.18 GiB (2.2%)
  SMART Message: Unable to run smartctl. Root privileges required.
  ID-1: /dev/sda maj-min: 8:0 vendor: Samsung model: SSD 870 EVO 500GB size: 465.76 GiB
    block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s tech: SSD serial: <filter>
    fw-rev: 2B6Q scheme: GPT
  ID-2: /dev/sdb maj-min: 8:16 vendor: SanDisk model: SSD PLUS 480GB size: 447.13 GiB block-size:
    physical: 512 B logical: 512 B speed: 6.0 Gb/s tech: SSD serial: <filter> fw-rev: 04RL
    scheme: GPT
Partition:
  ID-1: / raw-size: 446.88 GiB size: 438.79 GiB (98.19%) used: 20.17 GiB (4.6%) fs: ext4
    dev: /dev/sdb2 maj-min: 8:18
  ID-2: /boot/efi raw-size: 256 MiB size: 252 MiB (98.46%) used: 8.7 MiB (3.5%) fs: vfat
    dev: /dev/sdb1 maj-min: 8:17
Swap:
  Kernel: swappiness: 15 (default 60) cache-pressure: 100 (default) zswap: no
  ID-1: swap-1 type: file size: 8 GiB used: 0 KiB (0.0%) priority: -2 file: /swap/swap
Sensors:
  System Temperatures: cpu: 32.5 C mobo: N/A gpu: amdgpu temp: 41.0 C mem: 45.0 C
  Fan Speeds (rpm): N/A gpu: amdgpu fan: 693
Repos:
  Packages: pm: dpkg pkgs: 2455 libs: 1310 tools: apt, apt-get, aptitude, nala, synaptic pm: rpm
    pkgs: 0 pm: flatpak pkgs: 0
  No active apt repos in: /etc/apt/sources.list
  Active apt repos in: /etc/apt/sources.list.d/debian.sources
    1: deb http://deb.debian.org/debian/ trixie main  contrib non-free non-free-firmware
    2: deb http://security.debian.org/debian-security/ trixie-security main  contrib non-free non-free-firmware
    3: deb http://deb.debian.org/debian/ trixie-updates  main contrib non-free non-free-firmware
  Active apt repos in: /etc/apt/sources.list.d/mx.sources
    1: deb https://mxrepo.com/mx/repo/ trixie main non-free
Info:
  Memory: total: 64 GiB available: 62.53 GiB used: 2.39 GiB (3.8%)
  Processes: 417 Power: uptime: 1h 20m states: freeze,mem,disk suspend: deep avail: s2idle
    wakeups: 0 hibernate: platform avail: shutdown, reboot, suspend, test_resume image: 24.96 GiB
    services: upowerd,xfce4-power-manager Init: systemd v: 257 default: graphical tool: systemctl
  Compilers: gcc: 14.2.0 Client: shell wrapper v: 5.2.37-release inxi: 3.3.38
Boot Mode: UEFI

[andyprough]

my custom Linux distro

So you came here to complain that the Pale Moon developers did not have your own personal spin in mind when they built the downloadable binary tarballs? Is that the complaint here?

I can tell you it works beautifully on MX, Trisquel and antiX, and by extension is almost certain to run well on the Debian and Ubuntu distros that MX, Trisquel and antiX are derived directly from. And since Debian and Ubuntu and their child distros represent probably ~80% of all installed desktop distros, maybe you should be thinking about what exactly is not working properly on your personal custom distro and try to bring its performance more in line with the majority of distros.

[daveb]

It's a generic Linux system. Nothing special or weird about it. gcc 14. glibc 2.32. etc. Pretty straightforward.

PaleMoon simply DOES NOT RESPOND WELL when the CPU is under load, such as when compiling things in the background. It PAUSES FOR 3-5 SECONDS. Unlike Chromium, Firefox, and WebKit browsers.

(I'm getting a feeling of deja vu here. Almost like I just said this exact thing.)

It's real simple, guys. Nothing complex or difficult to understand going on here. I'm not a noob, or idiot, and no, it's not the fault of my system. (If only I had a nickel...)

I didn't come here to "complain" about anything. I just told you what the problem is. In fact, it seems I was being very nice. I even thanked you. What more do you want?

I'm not putting up with any abuse. If your attitude is "it's your fault", goodbye.

[daveb]

And by the way--NO, I did not download any binary tarballs. I compiled the damn browser from scratch. Just like all the 1,500 other packages on my custom distro. FYI.

[Moonchild]

It's real simple, guys. Nothing complex or difficult to understand going on here. I'm not a noob, or idiot, and no, it's not the fault of my system.

If this is true, then I wonder why I had to delete several posts from the moderation queue with F-bombs in them and attacking people for simply asking you to provide details we absolutely need to be able to help you, like information about your system and troubleshooting information from the browser. A seasoned expert like yourself should know better. It's real simple, indeed.

Especially if it's a custom build on a custom distro, our ability to help depends heavily on you working with us and not blowing your top right away. There is no such thing as a "generic Linux system" when you are using an LFS setup; that is literally the opposite of a generic Linux system. Also, we knew nothing about your hardware or what exactly you are doing to stress your system from your first very concise post.

Also:

The main problem is long (3-5+ second) pauses, especially when there's any kind of background disk or CPU activity.

"any kind of background disk or cpu activity" being blocking is not typical for Linux, and does point to something being "not generic". So that's what we go by, but the situation is now further explained with:

when the CPU is under load, such as when compiling things in the background

What you seem to be confusing is the apparent UI responsiveness of multi-process browsers compared to a single-process application when you are literally swamping the CPU and I/O. Pale Moon might indeed not do very well if you starve a system of compute resources because it doesn't use a dedicated process to feign responsiveness while content processes are just as slow in the background. If you're not a noob as claimed, then you certainly are aware of the nice tool in Linux to bump the niceness level of your compilation up?

Considering the overall tone in the disapproved posts, though, I don't think you're interested in actually troubleshooting here, but would rather attack anyone asking for details about your custom setup, let alone details about your hardware, so I'll leave it here and go get my coffee, instead

Also, please (re-)read the note "Before you begin" here: https://developer.palemoon.org/build/

[frostknight]

I'm using the latest PaleMoon on my custom Linux distro. Unfortunately, performance of this browser is very poor compared to Chromium or WebKit. The main problem is long (3-5+ second) pauses, especially when there's any kind of background disk or CPU activity. Otherwise it's great, and is a nice blast from the past. I'd love to use it more if/when the threading model is improved. Thanks for your work on PaleMoon.

What does this say:

about:buildconfig

Show us a screenshot of what you see at that location. That might help.

Also, I use a DIY distro too, it works fine for me. I am not even using 2GB of ram. load average is .60 in htop and I have like 5 tabs open in palemoon right now.
Cpu usage with 4 cores is less than 30% of one of the cores.
I am now curious what your hardware specs are.

You could also screenshot from top or htop how much resources being used. (recommend the 2nd option)

[andyprough]

such as when compiling things in the background

Yeah, I could see that, but I don't use chromium based browsers or Firefox forks during heavy compilation because they chew up way too much ram and the worst situation is an oom related crash mid-build. In that particular situation I'd rather deal with a UXP browser with lower memory usage and possibly slow GUI responsiveness under load, or often I just use links2 in the terminal while doing heavy compilation.

If your attitude is "it's your fault", goodbye.

Well, if you got the changes you wanted for fake GUI responsiveness while under heavy load, you would just have a bloated ram busting browser again. I don't think you are going to get everything you want, without spending a ton of money on an insanely powerful CPU, like maybe one of those ~$10,000 threadrippers that are built for Hollywood CGI workstations. Anyway, good luck.

[UCyborg]

To be fair, you can do things in multi-process browsers in other tabs while one tab is chewing on something. With Pale Moon, everything's waiting on that tab in this case. I wouldn't call being able to do things elsewhere "fake GUI responsiveness", it's quite real.

But this is one thing that falls on dead ears here. It is what it is.

[andyprough]

To be fair, you can do things in multi-process browsers in other tabs while one tab is chewing on something.

But that's a different matter than having all CPU cores pinned at 100% by some compilation process. You're just talking about resource usage amongst multiple tabs, but the same thing applies there - you are paying a price in terms of resources when every tab is a complete separate process.

[Basilisk-Dev]

I'm not a noob, or idiot, and no, it's not the fault of my system.)

Watching your interactions and mannerisms and your short temper with others within this thread certainly convinced me that you are those things, and possibly more expletives that I won't mention here.

I'm not putting up with any abuse. If your attitude is "it's your fault", goodbye.

No one is abusing you.

You came here complaining about an issue with no other details. I'm not saying your issue is not valid, but you provided no other info which makes it hard to tell if it is a valid issue or not.

Due to the lack of info, people rightfully asked you for more information. Then you got pissed because people asked you about your OS configuration and how you built the browser, both of which are extremely important questions that community members need in order to help you/us troubleshoot your performance issue.

If you can't provide simple troubleshooting information when asked and instead choose to go on a rampage, why would we help you? How do you expect us to resolve the issue without the required info? The community is happy to help you, but not when you immediately jump to negative conclusions and when you can't handle your temper when being asked a question.

This isn't a paid customer support service. We aren't obligated to help you. If you're an asshole we'll just help someone else who is less hostile.

If you want to chill out and reflect on why your communications and interactions with others garnered the reactions you received, we'd be happy to help you.

I'm not moderator here but I think this thread should be locked.

[UCyborg]

To be fair, you can do things in multi-process browsers in other tabs while one tab is chewing on something.

But that's a different matter than having all CPU cores pinned at 100% by some compilation process. You're just talking about resource usage amongst multiple tabs, but the same thing applies there - you are paying a price in terms of resources when every tab is a complete separate process.

It's just something I thought about when multi-process was brought up. But yeah, I rather just not do anything if compiling takes all CPU cores. It feels like asking to get beyond hardware capabilities, even more if compilation writes on the same storage medium where the browser profile is located.

Still, I find the phenomenon the OP described strange. Logically, what goes on in multi-process browsers' tabs should still be slowed down if all CPU cores are busy. I noticed on one page in app at work when busy in Edge, you can still scroll the page with content generated before it got busy, but everything inside was unresponsive to clicks, which is expected.

[andyprough]

Logically, what goes on in multi-process browsers' tabs should still be slowed down if all CPU cores are busy. I noticed on one page in app at work when busy in Edge, you can still scroll the page with content generated before it got busy, but everything inside was unresponsive to clicks, which is expected.

But isn't that scrolling vs non-scrolling behavior while locked up just a characteristic of how the developers decide to display the page, rather than a real resource or capability issue?

For example, when I open a "save-as" dialog box in XFCE, I can move the box around and see the document behind it. But the same dialog box in Gnome covers the document and refuses to be moved out of the way to read the document underneath. Just a difference in design style, rather than a difference in capability, from my perspective.

[Bilbo47]

Agree when running any decent-size app while compiling in the background, normal high-performance is not a reasonable expectation - regardless of whether the app is multi-threaded or single-threaded. Options include: sequester the compile to only certain cores; dedicate one core to interactive apps; compile on one virtual or actual machine and do interactive usage on another. Waste other people's time here is not an acceptable option.

[frostknight]

This isn't a paid customer support service. We aren't obligated to help you. If you're an asshole we'll just help someone else who is less hostile.

If you want to chill out and reflect on why your communications and interactions with others garnered the reactions you received, we'd be happy to help you.

I'm not moderator here but I think this thread should be locked.

I am still inclined to give him another chance, but I am waiting for him to respond to my comment.

If he doesn't give more info though and doesn't plan to, then I will agree locking makes sense.

[Moonchild]

I'm pretty sure OP has left the building. Locking.