Firefox memory eater freezing

[Sam_]

Open about 40 tabs and pin them, plus two tabs unpinned.
Every session those tabs are kept and reopened.
Firefox uses 2,3 GB RAM and freezes. (screenshot of conky)

I need to close firefox and shut down the machine after every session because after suspend and having firefox left open it is unusable.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: firefox 38.0+build3-0ubuntu0.14.04.1
ProcVersionSignature: Ubuntu 3.13.0-55.94-generic 3.13.11-ckt20
Uname: Linux 3.13.0-55-generic x86_64
AddonCompatCheckDisabled: False
ApportVersion: 2.14.1-0ubuntu3.11
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: zookeeper 1963 F.... pulseaudio
 /dev/snd/controlC0: zookeeper 1963 F.... pulseaudio
 /dev/snd/pcmC0D0p: zookeeper 1963 F...m pulseaudio
BuildID: 20150511103818
Channel: Unavailable
CurrentDesktop: Unity
Date: Mon Jul 6 15:52:41 2015
DefaultProfileIncompatibleExtensions:
 Deutsch (DE) Language Pack - <email address hidden>
 English (GB) Language Pack - <email address hidden>
 Default - {972ce4c6-7e08-4474-a285-3208198ce6fd}
DefaultProfilePrefSources:
 prefs.js
 [Profile]/extensions/{6614d11d-d21d-b211-ae23-815234e1ebb5}/defaults/preferences/preferences.js
 [Profile]/<email address hidden>/defaults/preferences/preferences.js
ForcedLayersAccel: False
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2012-02-05 (1247 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120204)
IpRoute:
 default via 192.168.2.1 dev eth0 proto static
 192.168.2.0/24 dev eth0 proto kernel scope link src 192.168.2.102 metric 1
IwConfig:
 eth0 no wireless extensions.

 lo no wireless extensions.
MostRecentCrashID: bp-6df73c03-c69b-404c-b5a0-79a8f2150506
Profile1IncompatibleExtensions:
 Deutsch (DE) Language Pack - <email address hidden>
 English (GB) Language Pack - <email address hidden>
 Default - {972ce4c6-7e08-4474-a285-3208198ce6fd}
Profile1PrefSources:
 prefs.js
 [Profile]/<email address hidden>/defaults/preferences/preferences.js
Profiles:
 Profile0 (Default) - LastVersion=38.0/20150511103818 (In use)
 Profile1 - LastVersion=38.0/20150511103818 (In use)
RelatedPackageVersions:
 totem-mozilla 3.10.1-1ubuntu4
 icedtea-7-plugin 1.5-1ubuntu1
RfKill:

RunningIncompatibleAddons: True
SourcePackage: firefox
SubmittedCrashIDs:
 bp-6df73c03-c69b-404c-b5a0-79a8f2150506
 bp-c13399cb-b4b7-461b-8691-2a35f2141124
 bp-29e68126-501a-4da7-b9cd-225892140922
UpgradeStatus: Upgraded to trusty on 2014-08-12 (327 days ago)
WifiSyslog:

dmi.bios.date: 07/30/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0305
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: P5QLD PRO
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev X.0x
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0305:bd07/30/2009:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP5QLDPRO:rvrRevX.0x:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer

[Paul White (paulw2u)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to look at all reported bugs in a timely manner. You reported this bug in <YEAR>. There have been many changes in Ubuntu since that time. Your problem may have been fixed with some of the updates.

It would help us a lot if you could test on a currently supported Ubuntu version. When you test it and it is still an issue, kindly upload the updated logs by running only once:

apport-collect 1471822

and add any additional information that you think relevant. Alternatively, please confirm that this is no longer a problem and that we can close the report. If we do not hear from you the bug report will close itself in approximately two months time.

Thank you again for helping make Ubuntu better.

[Sam_ (and-sam)]

Nevertheless, thank you for taking the time to respond.
Since I've switched to chromium to work with lots of tabs there is no longer an issue.
Still I use firefox for "lightweight" surfing on a notebook.
From my side we can close this bug. Thanks.

[Paul White (paulw2u)]

Thanks for your reply Sam. As the bug was still marked as being "New" I'll close it by changing the status to "Invalid".