Hi vessto You can install as many Firefox versions and profiles as you want (Subject to Computer resources).

Yes it is relatively easy to do what you want. I have many multiple installs of Firefox on various machines.

However that may not be the best solution, in particular Nightly is the least stable version of Firefox and is not intended for trouble-free day-to-day browsing.

The next channel up (was Aurora) the "Development Edition" would be a better for day to day browsing. I usually use that as my default browser.

it is probably better to look at your problem more closely. You apparently have Windows 10 so presumably have a machine more than capable of running 15+ tabs & using image heavy sites. It would also be interesting to have the links to the advice you refer to. There is a new multi process feature on Firefox Nightly & DE but it is not fully ready and may cause problems.

You may be interested in looking at

• Firefox uses too much memory or CPU resources - How to fix
• Firefox uses too much memory or CPU resources - How to fix
• https://wiki.mozilla.org/RapidRelease#Release_timeline
• https://www.mozilla.org/en-US/firefox/channel/#developer

Indeed this problem appeared as all of a sudden, and in winter, no in hot days to blame temperatures. I never cleaned my PC inside as it was in service period. I turned off AVG Free Link Scanner. I forgot to say this happens when I dll too, especially on high speed (5-6 mbps). I tend to think some addon causes that, some who monitors all opened tabs and things on them, and all downloads.

I have AdBlock+ and NoScript which also should lessen the CPU usage. My hardware acceleration is turned on. Graphic card drive is up-to-date according to my attempts to update it from Device Manager.

After creating new small content-prefs.sqlite file the CPU usage is much lower on ordinary browsing. But when I open image sharing sites or download very fast it become 70-80%.

Here's the question I mentioned. It is old and locked now:

https://support.mozilla.org/en-US/questions/1003966

The second reply of shape5. He/she also mentions problems with Pinterest in their first reply.

I remember I did some changes in about:config but all were from replies from this site or Mozillazine.

PS. I have Browser Backgrounds addon and have imported custom images in it, around 200 MB. Dunno if they consume memory but it stays high (over 400 MB) even on blank page.

PPS. I noticed high CPU and memory on upload too, even with 400 kpbs.

The old locked thread was ather long and confusing. I am not sue uing sure using Nightly really helped more than the one person, and even then we do not know the reason for that. It could have been merely that using Nightly resulted in a new profile being used.

As for the temperature issuues when I see problems I ussually notice the fan/s notching up to full speed and if it does overheat past a critical limit it will probably cuttout completely. There is software that will monitor temperatures, for Windows one such utility is Speedfan.

Firefox using 200MB of memory is probably fairly low and normal.

Have you tried downloading and installing Developer Edition ? By default that installs separately from your standard Firefox and by default also uses it's own separate Profile.

it may be worth comparing InternetExplorer and Edge, do they have similar problems ?

edit typos - much easier typing on a desktop than a phone!

Note the Nightly and Aurora (developers edition) channel builds gets checkins almost everyday. This means there is a update each of those days and can sometimes cause issues until fixed, finished or reverted. Beta gets say six to 12 builds for a version.

Release < Beta (b#) < Aurora (a2) < Nightly (a1)

John99 said

The old locked thread was ather long and confusing. I am not sue uing Nightly really helped more thn the one peron, and even then weo not know the reason for that. It could have been merly that using Nightly resultedin a new profile being used. As for the temperature isuues when I see problems I ussually notice the fan/s nothing up to full speed and if it does oveheat past a critical limit it will probably cuttout completly. There is softwae tht will monitor temperatures, for Windows one such utility is Speedfan. Firefox using 200MB of memory is probably fairly low and normal. Have you tried downloding and installing Developer Edition ? By default that istalls separatly from your standar Firefox and by defult also uses it's own separate Profile. it may be worth comparing InternetExplorer and Edge, do they have similar problems ?

Maybe the sound that comes from my PC is the fan on full speed? My PC is all-in-one and some tend to think this type of PC have issues with heat. I have OpenHardwareMonitor Beta and my disc is around 51-53 and CPU 55-60 during normally browsing with FF and 65-70 when downloading, uploading, using sites with Flash Player and in images-heavy sites. Is Speedfan only monitoring program or will increase the speed so my PC to be better cooled? I also have external cooler but it's not much strong.

I don't use IE from ages nor keen to use Edge now. But when I download from Opera the CPU is normal. It has AdBlock+ too. But overall with Flash Player I have same issues in FF, Opera, Opera Beta and Chrome.

Where to find Developer's Edition? I'd definitely try it and will add my current addons one by one to see when the problem will occur.

Off topic: Sorry, I don't wanna sound annoying but I saw the typos in your reply. I had similar problem after my upgrade to Win 10 but then solved it. Letters were cut because slow reaction of the graphic card.

EDIT: Tested in Opera with heavy site - Soundcloud with around 150 songs on the page. Till added them in the downloading addon the CPU went crazy as memory too. I wonder if my pagefile is proper to be 6 GB although it is exactly 1.5x the RAM. Maybe I can try overclocking my CPU if it not dangerous. It is Intel Celeron 2.5 GHz.

My first post had a link to one of the Developer Edition pages where you may get a download: mozilla.org/firefox/channel/#developer

Speedfan charts the temperature so you can see how hot it is getting. I am not in Windows at the moment for checking Speedfan's features but I doubt anything will control the fan speed of an all in one, as I imagine it will have only the one fan. IIRC I did find something for Windows that could close it down safely once a particular temperature was reached next time I am using Windows I will try to look it up.

This is not the place to discuss overclocking, that would be better discussed on a hardware, gaming or Windows forum, but I suggest you avoid overclocking it will likely make overheating even worse. (Speedfan may well provide overclocking)

If you have similar problems on other browsers with CPU usage it probably is not a Firefox issue that you are suffering from. Using separate profiles and a minimum number of Open Tabs may help.

Yeah, sorry, I saw the link later. But after checking Opera too I started to think my AVG Free has something to do with the issues although I disable Link Scanner. Moreover, I remember probs started in winter, and my antivir has new upgrades that time. I need to look over in my PC settings or other software which can interfere in the work of the browsers.

Even now with only this tab opened FF uses 600-700 MB memory while CPU is 2-3%.

Agree about overclocking, I remember a gamer I knew who has overclocked his PC (tower type) has added 4 more fans inside.

You may use Firefox's built in about:memory an: interactive, real time tool, with explanations on mouseover of items & button to reduce memory. That will show where memory is used

• https://developer.mozilla.org/docs/Mozilla/Performance/about:memory

( For information on detailed memory use of a specific individual open tab Pre Release versions, and probably future versions have a graphical utility

• https://developer.mozilla.org/docs/Tools/Memory/Tree_Map_view )

John99 said

You may use Firefox's built in about:memory an: interactive, real time tool, with explanations on mouseover of items & button to reduce memory. That will show where memory is used

• https://developer.mozilla.org/docs/Mozilla/Performance/about:memory

( For information on detailed memory use of a specific individual open tab Pre Release versions, and probably future versions have a graphical utility

• https://developer.mozilla.org/docs/Tools/Memory/Tree_Map_view )

Thank you, used about:memory to see Measure. Too complicated for me but will try to get it.