6 ms·

If this release makes it actually usable on MacOS I would be so happy. Everyone says to use FireFox here, but they don't realize that it runs horribly on machin

If this release makes it actually usable on MacOS I would be so happy. Everyone says to use FireFox here, but they don't realize that it runs horribly on machines that a lot of people use to develop on. Reading the release notes: Improved performance for Mac and Linux users, by enabling link time optimization (Clang LTO). (Clang LTO was enabled for Windows users in Firefox 63.) Doesn't seem like this fixes the high CPU issue on MacOS. Maybe in another few dozen releases they'll fix it. Doesn't Mozilla realize how many people develop on MacOS? Everyone I know develops on a Mac.

nindalf 8y ago
To be clear, this doesn't affect all macOS users. My battery reliably lasts a whole day with Firefox running throughout. That said, the subset of users who are affected, like you, suffer a lot - low prevalence, high impact.
- jasin 8y ago
  In my case, CPU usage goes to the roof if I use a scaled resolution instead of the default one. If that is the case with all macOS users with non-default resolution, I wouldn't call it low prevalence.
  - lars_francke 8y ago
    You can work around this (not ideal I know) by enabling "Low Resolution" mode for Firefox only: https://support.apple.com/en-us/HT202471 https://support.apple.com/en-us/HT202471 (I have the same issue and I'd like to switch to Firefox)
  - jillesvangurp 8y ago
    Not an issue for me. I have a imac 5K and a retina mac book pro. Both with image scaling on by default. I think most recent macs have retina now. I use Firefox exclusively and have done so for the last 2 years or so. This sounds like it could be a driver issue for specific macs. Both my macs have AMD Radeon chipsets & quad core i7s. Anyway, I'm sure this issue is real. Bugzilla ticket numbers probably exist for it and might be more helpful than vague complaints about things being slow. Of course some web sites are a bit unreasonably javascript heavy these days. The downside of a large screen is that pushing a lot of pixels around is not free. Usually closing any offending tabs immediately restores any cpu usage I see. I'd suggest using the new task manager thingy (page menu->more->task manager)
    - cpmsmith 8y ago
      Anecdotal, but I've found it happens when image scaling by a factor other than 2. Affects my setup of a 4K display at 2650x1440 effective resolution, or 1.5x scaling.
      - rosser 8y ago
        Exactly this. I run at 1920x1080 effective resolution on my 15" rMBP, and 1680x945 on my 13". I see the issue on both. When I switch to the "default" scaling (1440x900 and 1280x800, respectively), it stops. Only the 15" has a discrete GPU, eliminating that as potentially causal. The "problem" scaling is 1.5x. The default is 2x.
- deleted 8y ago
  [deleted]
Paul-ish 8y ago
When I interned at Mozilla, most of the FF devs developed on a Mac. They are not ignoring the platform. I suspect the issue is as other said, low incidence, high impact. It seems like they are aware of the issue: https://bugzilla.mozilla.org/show_bug.cgi?id=1404042 https://bugzilla.mozilla.org/show_bug.cgi?id=1404042
acdha 8y ago
I use only Macs by default. It runs great and has for years. There's probably a real issue somewhere but it's far from as universal as your post implies.
- jillesvangurp 8y ago
  Likewise. Not aware of any weird issues with performance in relation to Firefox. I use it exclusively. I'm on the beta channel. I can't remember the last time I had a browser crash. I generally restart it to apply new updates every few days or so. If you have performance issues; you might want to check whether you need to blame the browser or some of your extensions.
  - acdha 8y ago
    Seconding your last point — almost every time I've had someone complain about generic Firefox or Chrome performance the problem went away as soon as they restarted it without extensions. There are certainly exceptions but misattribution is common enough that I'm not surprised to see browser vendors adding the UI to make it easier to discover.
    - rosser 8y ago
      This specific problem is one of those exceptions. This is a known issue, and has been around since at least v57. There are multiple Bugzilla issues on it. The cause is known. It isn't extensions. The fix is just invasive, and apparently ongoing.
      - acdha 8y ago
        That’s true but not what this thread was about. The person I responded to above was making a very broad claim, which is wrong, and jillesvangurp agreed with the observation and added a general point which is correct. There is a specific issue affecting a subset of people with less common configurations but that doesn’t make the sweeping claim true or the recognition that browser performance issues are notoriously poorly attributed untrue.

nindalf 8y ago

To be clear, this doesn't affect all macOS users. My battery reliably lasts a whole day with Firefox running throughout. That said, the subset of users who are affected, like you, suffer a lot - low prevalence, high impact.

jasin 8y ago
In my case, CPU usage goes to the roof if I use a scaled resolution instead of the default one. If that is the case with all macOS users with non-default resolution, I wouldn't call it low prevalence.
- lars_francke 8y ago
  You can work around this (not ideal I know) by enabling "Low Resolution" mode for Firefox only: https://support.apple.com/en-us/HT202471 https://support.apple.com/en-us/HT202471 (I have the same issue and I'd like to switch to Firefox)
- jillesvangurp 8y ago
  Not an issue for me. I have a imac 5K and a retina mac book pro. Both with image scaling on by default. I think most recent macs have retina now. I use Firefox exclusively and have done so for the last 2 years or so. This sounds like it could be a driver issue for specific macs. Both my macs have AMD Radeon chipsets & quad core i7s. Anyway, I'm sure this issue is real. Bugzilla ticket numbers probably exist for it and might be more helpful than vague complaints about things being slow. Of course some web sites are a bit unreasonably javascript heavy these days. The downside of a large screen is that pushing a lot of pixels around is not free. Usually closing any offending tabs immediately restores any cpu usage I see. I'd suggest using the new task manager thingy (page menu->more->task manager)
  - cpmsmith 8y ago
    Anecdotal, but I've found it happens when image scaling by a factor other than 2. Affects my setup of a 4K display at 2650x1440 effective resolution, or 1.5x scaling.
    - rosser 8y ago
      Exactly this. I run at 1920x1080 effective resolution on my 15" rMBP, and 1680x945 on my 13". I see the issue on both. When I switch to the "default" scaling (1440x900 and 1280x800, respectively), it stops. Only the 15" has a discrete GPU, eliminating that as potentially causal. The "problem" scaling is 1.5x. The default is 2x.
deleted 8y ago
[deleted]

Paul-ish 8y ago

When I interned at Mozilla, most of the FF devs developed on a Mac. They are not ignoring the platform. I suspect the issue is as other said, low incidence, high impact. It seems like they are aware of the issue: https://bugzilla.mozilla.org/show_bug.cgi?id=1404042 https://bugzilla.mozilla.org/show_bug.cgi?id=1404042

acdha 8y ago

I use only Macs by default. It runs great and has for years. There's probably a real issue somewhere but it's far from as universal as your post implies.

jillesvangurp 8y ago
Likewise. Not aware of any weird issues with performance in relation to Firefox. I use it exclusively. I'm on the beta channel. I can't remember the last time I had a browser crash. I generally restart it to apply new updates every few days or so. If you have performance issues; you might want to check whether you need to blame the browser or some of your extensions.
- acdha 8y ago
  Seconding your last point — almost every time I've had someone complain about generic Firefox or Chrome performance the problem went away as soon as they restarted it without extensions. There are certainly exceptions but misattribution is common enough that I'm not surprised to see browser vendors adding the UI to make it easier to discover.
  - rosser 8y ago
    This specific problem is one of those exceptions. This is a known issue, and has been around since at least v57. There are multiple Bugzilla issues on it. The cause is known. It isn't extensions. The fix is just invasive, and apparently ongoing.
    - acdha 8y ago
      That’s true but not what this thread was about. The person I responded to above was making a very broad claim, which is wrong, and jillesvangurp agreed with the observation and added a general point which is correct. There is a specific issue affecting a subset of people with less common configurations but that doesn’t make the sweeping claim true or the recognition that browser performance issues are notoriously poorly attributed untrue.