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Memory usage between Mac and Windows using a sync'd profile

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  • Last reply by user633449

mike foley
mike foley
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I'm running a 2015 Macbook Retina with MacOS 10.12.6. It's running Firefox 54.0.1.

On that system I run a Windows 10 VM in VMware Fusion. That also has Firefox 54.0.1 installed.

Both browsers sync using Firefox Sync.

The Mac consistently uses about 1-2GB of memory (grows from 900MB to 2GB fairly quickly) Windows consistently uses about 400MB, sometimes grows to 500MB.

The Windows Firefox usually has MORE tabs open than the Mac! Mac: 16 tabs Windows: 10 tabs, usually over 20.

Performance on the Mac has been terrible to be quite honest. Lots of spinning beachballs for things like Facebook or videos or tab switching.

I'm trying to understand the reasons why the Mac Firefox is using twice the memory and feels a lot more sluggish than the Windows Firefox. Let me know if you need anything. I'd really rather not destroy my profile. That really is a painful exercise.

thanks mike

I'm running a 2015 Macbook Retina with MacOS 10.12.6. It's running Firefox 54.0.1. On that system I run a Windows 10 VM in VMware Fusion. That also has Firefox 54.0.1 installed. Both browsers sync using Firefox Sync. The Mac consistently uses about 1-2GB of memory (grows from 900MB to 2GB fairly quickly) Windows consistently uses about 400MB, sometimes grows to 500MB. The Windows Firefox usually has MORE tabs open than the Mac! Mac: 16 tabs Windows: 10 tabs, usually over 20. Performance on the Mac has been terrible to be quite honest. Lots of spinning beachballs for things like Facebook or videos or tab switching. I'm trying to understand the reasons why the Mac Firefox is using twice the memory and feels a lot more sluggish than the Windows Firefox. Let me know if you need anything. I'd really rather not destroy my profile. That really is a painful exercise. thanks mike

Chosen solution

One thing that jumps out right away is that you have ALOT of extensions. This has a tendency to dramatically increase Firefox resource consumption (especially when syncing lots of add-on preferences). I'd suggest you remove any add-ons you don't use (it looks like you may have some that are duplicating efforts)

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user633449
user633449
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Chosen Solution

One thing that jumps out right away is that you have ALOT of extensions. This has a tendency to dramatically increase Firefox resource consumption (especially when syncing lots of add-on preferences). I'd suggest you remove any add-ons you don't use (it looks like you may have some that are duplicating efforts)

mike foley
mike foley Question owner
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Ok, I cleaned out a bunch, synced both browsers and still, the Windows Firefox runs with more than half the amount of memory than Mac.

Now at 806MB on Mac and 295MB on Windows.

Same extensions with the exception of Webex.

Is there a way to investigate where memory is being consumed?

user633449
user633449
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You can look at about:memory (type it into the URL bar and press enter).


Also remember, Windows and Mac are different platforms that allocate memory differently. You can't expect a program to use the same amount of memory on two completely different Operating systems. The memory allocations you listed aren't insane by any measure. I know you said you see performance issues with your Mac, they probably aren't caused by high memory usage (memory is designed to be used, as long as you have enough the more a program can use generally the faster it will run. Unused memory is wasted memory.)