Firefox is very slow

Hello I have recently installed Manjaro gnome on my 2012 iMac. And it is running extremely slow on firefox.

Things I have done:

  • Updated Manjaro
  • tried out different performance settings in Firefox
  • Started Firefox in safe mode

Things to note:

  • Win10 didn’t have this issue with Firefox
  • Chromium is much faster then Firefox

System info:

> System:
>   Kernel: 5.15.7-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0
>     parameters: BOOT_IMAGE=/boot/vmlinuz-5.15-x86_64
>     root=UUID=8fe8066e-dad6-4093-aea3-a659f6e0cbaf rw quiet splash apparmor=1
>     security=apparmor resume=UUID=8e0689ff-7304-457c-8ff4-c38e121cc59a
>     udev.log_priority=3
>   Desktop: GNOME 41.2 tk: GTK 3.24.30 wm: gnome-shell dm: GDM 41.0
>     Distro: Manjaro Linux base: Arch Linux
> Machine:
>   Type: Desktop System: Apple product: iMac13,2 v: 1.0
>     serial: <superuser required> Chassis: type: 13 v: Mac-FC02E91DDD3FA6A4
>     serial: <superuser required>
>   Mobo: Apple model: Mac-FC02E91DDD3FA6A4 v: iMac13,2
>     serial: <superuser required> UEFI: Apple v: 287.0.0.0.0 date: 06/13/2019
> Battery:
>   Message: No system battery data found. Is one present?
> Memory:
>   RAM: total: 15.57 GiB used: 10.7 GiB (68.7%)
>   RAM Report:
>     permissions: Unable to run dmidecode. Root privileges required.
> CPU:
>   Info: model: Intel Core i5-3470S bits: 64 type: MCP arch: Ivy Bridge
>     family: 6 model-id: 0x3A (58) stepping: 9 microcode: 0x21
>   Topology: cpus: 1x cores: 4 smt: <unsupported> cache: L1: 256 KiB
>     desc: d-4x32 KiB; i-4x32 KiB L2: 1024 KiB desc: 4x256 KiB L3: 6 MiB
>     desc: 1x6 MiB
>   Speed (MHz): avg: 1596 high: 1597 min/max: 1600/3600 scaling:
>     driver: intel_cpufreq governor: schedutil cores: 1: 1596 2: 1597 3: 1597
>     4: 1597 bogomips: 23159
>   Flags: acpi aes aperfmperf apic arat arch_perfmon avx bts clflush cmov
>     constant_tsc cpuid cpuid_fault cx16 cx8 de ds_cpl dtes64 dtherm dts ept erms
>     est f16c flexpriority flush_l1d fpu fsgsbase fxsr ht ibpb ibrs ida lahf_lm
>     lm mca mce md_clear mmx monitor msr mtrr nonstop_tsc nopl nx pae pat pbe
>     pcid pclmulqdq pdcm pebs pge pln pni popcnt pse pse36 pti pts rdrand
>     rdtscp rep_good sep smep smx ss ssbd sse sse2 sse4_1 sse4_2 ssse3 stibp
>     syscall tm tm2 tpr_shadow tsc tsc_deadline_timer vme vmx vnmi vpid x2apic
>     xsave xsaveopt xtopology xtpr
>   Vulnerabilities:
>   Type: itlb_multihit status: KVM: VMX disabled
>   Type: l1tf
>     mitigation: PTE Inversion; VMX: conditional cache flushes, SMT disabled
>   Type: mds mitigation: Clear CPU buffers; SMT disabled
>   Type: meltdown mitigation: PTI
>   Type: spec_store_bypass
>     mitigation: Speculative Store Bypass disabled via prctl and seccomp
>   Type: spectre_v1
>     mitigation: usercopy/swapgs barriers and __user pointer sanitization
>   Type: spectre_v2 mitigation: Full generic retpoline, IBPB: conditional,
>     IBRS_FW, STIBP: disabled, RSB filling
>   Type: srbds status: Vulnerable: No microcode
>   Type: tsx_async_abort status: Not affected
> Graphics:
>   Device-1: NVIDIA GK107M [GeForce GTX 660M Mac Edition] vendor: Apple
>     driver: nvidia v: 390.144 alternate: nouveau,nvidia_drm bus-ID: 01:00.0
>     chip-ID: 10de:0fe0 class-ID: 0300
>   Device-2: Apple FaceTime HD Camera (Built-in) type: USB driver: uvcvideo
>     bus-ID: 1-1.1:3 chip-ID: 05ac:8511 class-ID: 0e02 serial: <filter>
>   Display: x11 server: Xorg 1.21.1.2 compositor: gnome-shell driver:
>     loaded: nvidia resolution: <missing: xdpyinfo>
>   Message: Unable to show advanced data. Required tool glxinfo missing.
> Audio:
>   Device-1: Intel 7 Series/C216 Family High Definition Audio
>     driver: snd_hda_intel v: kernel bus-ID: 00:1b.0 chip-ID: 8086:1e20
>     class-ID: 0403
>   Device-2: NVIDIA GK107 HDMI Audio driver: snd_hda_intel v: kernel
>     bus-ID: 01:00.1 chip-ID: 10de:0e1b class-ID: 0403
>   Sound Server-1: ALSA v: k5.15.7-1-MANJARO running: yes
>   Sound Server-2: JACK v: 1.9.19 running: no
>   Sound Server-3: PulseAudio v: 15.0 running: yes
>   Sound Server-4: PipeWire v: 0.3.40 running: no
> Network:
>   Device-1: Broadcom NetXtreme BCM57766 Gigabit Ethernet PCIe vendor: Apple
>     driver: tg3 v: kernel port: N/A bus-ID: 03:00.0 chip-ID: 14e4:1686
>     class-ID: 0200
>   IF: enp3s0f0 state: up speed: 100 Mbps duplex: full mac: <filter>
>   IP v4: <filter> type: dynamic noprefixroute scope: global
>     broadcast: <filter>
>   IP v6: <filter> type: dynamic noprefixroute scope: global
>   IP v6: <filter> type: noprefixroute scope: link
>   Device-2: Broadcom BCM4331 802.11a/b/g/n driver: bcma-pci-bridge v: N/A
>     modules: bcma bus-ID: 04:00.0 chip-ID: 14e4:4331 class-ID: 0280
>   IF-ID-1: wlp4s0b1 state: down mac: <filter>
>   WAN IP: <filter>
> Bluetooth:
>   Device-1: Apple Bluetooth USB Host Controller type: USB driver: btusb v: 0.8
>     bus-ID: 2-1.8.1.3:7 chip-ID: 05ac:828b class-ID: fe01
>   Report: rfkill ID: hci0 rfk-id: 1 state: up address: see --recommends
> Logical:
>   Message: No logical block device data found.
> RAID:
>   Message: No RAID data found.
> Drives:
>   Local Storage: total: 1.82 TiB used: 180.86 GiB (9.7%)
>   SMART Message: Required tool smartctl not installed. Check --recommends
>   ID-1: /dev/sda maj-min: 8:0 vendor: Samsung model: SSD 860 EVO 2TB
>     size: 1.82 TiB block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s
>     type: SSD serial: <filter> rev: 3B6Q scheme: GPT
>   Message: No optical or floppy data found.
> Partition:
>   ID-1: / raw-size: 1.8 TiB size: 1.77 TiB (98.37%) used: 180.56 GiB (9.9%)
>     fs: ext4 dev: /dev/sda2 maj-min: 8:2 label: N/A
>     uuid: 8fe8066e-dad6-4093-aea3-a659f6e0cbaf
>   ID-2: /boot/efi raw-size: 300 MiB size: 299.4 MiB (99.80%)
>     used: 288 KiB (0.1%) fs: vfat dev: /dev/sda1 maj-min: 8:1 label: NO_LABEL
>     uuid: FC1C-8134
> Swap:
>   Kernel: swappiness: 60 (default) cache-pressure: 100 (default)
>   ID-1: swap-1 type: partition size: 17.12 GiB used: 307.3 MiB (1.8%)
>     priority: -2 dev: /dev/sda3 maj-min: 8:3 label: swap
>     uuid: 8e0689ff-7304-457c-8ff4-c38e121cc59a
> Unmounted:
>   Message: No unmounted partitions found.
> USB:
>   Hub-1: 1-0:1 info: Full speed or root hub ports: 2 rev: 2.0 speed: 480 Mb/s
>     chip-ID: 1d6b:0002 class-ID: 0900
>   Hub-2: 1-1:2 info: Intel Integrated Rate Matching Hub ports: 6 rev: 2.0
>     speed: 480 Mb/s chip-ID: 8087:0024 class-ID: 0900
>   Device-1: 1-1.1:3 info: Apple FaceTime HD Camera (Built-in) type: Video
>     driver: uvcvideo interfaces: 3 rev: 2.0 speed: 480 Mb/s power: 500mA
>     chip-ID: 05ac:8511 class-ID: 0e02 serial: <filter>
>   Hub-3: 2-0:1 info: Full speed or root hub ports: 2 rev: 2.0
>     speed: 480 Mb/s chip-ID: 1d6b:0002 class-ID: 0900
>   Hub-4: 2-1:2 info: Intel Integrated Rate Matching Hub ports: 8 rev: 2.0
>     speed: 480 Mb/s chip-ID: 8087:0024 class-ID: 0900
>   Hub-5: 2-1.8:3 info: Microchip (formerly SMSC) ports: 1 rev: 2.0
>     speed: 480 Mb/s power: 2mA chip-ID: 0424:2412 class-ID: 0900
>   Hub-6: 2-1.8.1:4
>     info: Broadcom BCM2046B1 USB 2.0 Hub (part of BCM2046 Bluetooth) ports: 3
>     rev: 2.0 speed: 12 Mb/s power: 94mA chip-ID: 0a5c:4500 class-ID: 0900
>   Device-1: 2-1.8.1.3:7 info: Apple Bluetooth USB Host Controller
>     type: Bluetooth driver: btusb interfaces: 4 rev: 2.0 speed: 12 Mb/s
>     chip-ID: 05ac:828b class-ID: fe01
>   Hub-7: 3-0:1 info: Hi-speed hub with single TT ports: 4 rev: 2.0
>     speed: 480 Mb/s chip-ID: 1d6b:0002 class-ID: 0900
>   Device-1: 3-1:2 info: Logitech G203 Gaming Mouse type: Mouse,HID
>     driver: hid-generic,usbhid interfaces: 2 rev: 2.0 speed: 12 Mb/s
>     power: 300mA chip-ID: 046d:c084 class-ID: 0300 serial: <filter>
>   Device-2: 3-2:3 info: Logitech Illuminated Keyboard type: Keyboard,Mouse
>     driver: hid-generic,usbhid interfaces: 2 rev: 2.0 speed: 12 Mb/s
>     power: 300mA chip-ID: 046d:c318 class-ID: 0300
>   Hub-8: 4-0:1 info: Super-speed hub ports: 4 rev: 3.0 speed: 5 Gb/s
>     chip-ID: 1d6b:0003 class-ID: 0900
> Sensors:
>   System Temperatures: cpu: 55.0 C mobo: N/A gpu: nvidia temp: 49 C
>   Fan Speeds (RPM): N/A
> Info:
>   Processes: 224 Uptime: 22d 13h 13m wakeups: 31985 Init: systemd v: 249
>   tool: systemctl Compilers: gcc: 11.1.0 Packages: pacman: 1202 lib: 327
>   flatpak: 0 Shell: Zsh v: 5.8 running-in: gnome-terminal inxi: 3.3.11

Try to run firefox in the terminal. You will see what error comes.

Trying in safe mode isn’t the same as trying with a clean profile with no extensions. You might want to backup your current profile first.

about:support- choose Refresh Firefox

Most FF issues can be traced back to corrupt profile or wonky extensions.

Is Enable DNS over HTTPS unchecked? in Settings-General-Network Settings

From your inxi output, it looks like your system is not fully updated. Please update your system as FF has also been updated and stable kernel is at 5.15.12.

Maybe it is similar to Problem with Firefox- Gecko Main pigging CPU after upgrade to 96, it is about HTTP3 bug.

There was no error from the terminal.

I did everything listed in the chat. And Firefox still scrolls slowly. Even with smooth scrolling on or off.

I disabled HTTP3 in advanced settings. Still no change.

Thanks for all the replys

You haven’t mentioned which version of FF is installed. Here is how it stands as of now:

firefox:
Stable: 96.0-0.1
Testing:96.0.1-1
Unstable:96.0.2-1

I updated to firefox:
Stable: 96.0-0.1