https://support.mozilla.org/en-US/questions/1003966 https://support.mozilla.org/en-US/questions/998289

Start Firefox in Safe Mode {web link} While you are in safe mode;

Type about:preferences<Enter> in the address bar

Select Advanced > General. Look for and turn off Use Hardware Acceleration.

Poke around safe web sites. Are there any problems?

Then restart.

Type about:addons<Enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac:<Command>)<Shift> A)

On the left side of the page, select Plugins. Go thru the list and set Everything to Ask.

BTW; At the top right is a link to check your plugins.

none of your suggestion is helpful,

i think you didn't even read my post, and decide to post the usual answer.

i tried to do what you are suggesting, but like i said, huge cpu usage spikes still happens a lot.

I had looked at those responses, and had not seen my suggestions. When you were in safe mode, was there any CPU problem?

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them.

@Fred : because you said that you didn't see anyone suggesting anything like yours, i decide to recheck my old post, about firefox 29, and if you look at the post right below mine, which was written by Moses,

and this is what moses wrote : Try to follow the steps listed below to see if this fixes the high CPU usage

   https://support.mozilla.org/kb/firefox-uses-too-much-memory-ram 

and after i recheck the link, its mentioned multiple times in it, to test firefox in safe mode, and obviously i tried it before, and i tried it again yesterday, and the result is still the same.

that's why i said the issue resurfaced again, after it was gone till yesterday update to firefox 33.

that's why your suggestion is familiar, is because it is the same suggestion that was given to me previously, and yes i did tried to disable all addons and plugins.

besides if you read my current issue, it is about high cpu usage only, the high RAM thing is still manageable, because its only high RAM, and not a memory leak.

reason for Edit : fixed typo

just to make this clear, i didn't add any kind of toolbar,

i'm a minimalistic person, i didn't like my browser to be filled with useless things.

one more time i will state that the only addons that i used are : 1. Adblock Plus 2. Flash Block 3. Classic Theme Restorer (this one is added after the issue show up on firefox 29).

and the only plugins that i use are standard plugins : 1. adobe flash 2. Java

and why is, every single time, peoples always assume, that a person that has issue, must have used tons of plugins and addons, while its not like that in reality.

now tell me does the addons and plugins that i use are excessive ?

heck i don't even need to use firefox classic, if it wasn't for firefox changing the UI to be similar to chrome, news flash for firefox dev, almost all of firefox users doesn't like google chrome.

Hi again DM789, Sorry you are having issues again.

I have not at present read through your other threads/posts.

I know you may not find Fred's comments helpful, but where there is no obvious cause it is normal troubleshooting strategy to try in safemode and with all plugins disabled.

If you are running into problms freezing and getting error messages the more of a basic default settup you can get to for testing the better. I did note you mention only

1. Adblock Plus 2. Flash Block 3. Classic Theme Restorer (this one is added after the issue show up on firefox 29).

and the only plugins that i use are standard plugins : 1. adobe flash 2. Java

But I also note from your details

    AutoProxy 0.4b2.2013051811 (autoproxy@autoproxy.org)
    Enhanced Steam 6.9 (jid0-SmvlvxGpvCyG252KbVMqIKR79Uc@jetpack)
    IDM CC 7.3.85 (mozilla_cc@internetdownloadmanager.com)
    Magrent 1.0.1 (jid1-9tZMAIdeuiEjHg@jetpack)
    AMD Steady Video 2.0 (steadyvideo@amd.com) (Inactive)
    Greasemonkey 2.1 ({e4a8a97b-f2ed-450b-b12d-ee082ba24781}) (Inactive)
    MEGA EXTENSION 1.0.3 (firefox@mega.co.nz) (Inactive)
    Memory Fox 7.4 ({E173B749-DB5B-4fd2-BA0E-94ECEA0CA55B}) (Inactive)

If you do want to look into this problem further the besy thing to do is probably to set up a new test profile and use that to run Firefox with noaddons at all with all the plugins disabled. (You may do that and leave your ordianary working profile alone). I can provide instructions butin fact the simplest method of doing that as a Windows user is to download and install the third party unoficial Firefox portable as an additional browser.

1. http://portableapps.com/apps/internet/firefox_portable
2. http://portableapps.com/apps/internet/firefox-portable-esr

It could in be worth trying both the standard vesion and esr IF you think the problem is only with the current Release, however you do seem to have had issues with earlier versions also.

If Firefox does start hanging there is a utility available that will show exactly what is hanging, and whilst I do not understand its output I am sure our professional helpdesk staff do, however it really is helpful to test intiially in safe mode and with no plugins to see if you still have the issue then.

well, the rest of the plugin that i mentioned is disabled most of the time, ex : enhanced steam is only enabled when i want to browse steam store, and i rarely do that, since nothing released lately excites me.

and only those 3 are always active.

but i do notice a few things : 1. with only this page opened, for writing reply, firefox is using between 0-30% CPU usage.

2. when i opened a page with only a few ads, the cpu usage can reach 100%. ex : guru3d forum (i disabled adblock there)

i'm providing this info, because maybe it can be of use.

and about the portable version, sure i'll give it a go, in fact, i used to use firefox portable quite often in the past.

can't remember why i decided not to use it anymore thought.

btw for more complete info : 1. autoproxy => never used it, unless my isp blocked a website i wanted to visit, but its never used anymore, since i found DNScrypt (not a firefox plugin).

2. IDM => disabled, because it can turn itself on, when it detect a download link.

3. Magrent => disabled, because i prefer to use website version.

4. AMD steady video => auto installed by AMD display driver, but i disabled it, because it fucked up youtube videos playback.

5. Mega Extension => again disabled, i don't think i ever enabled it anymore.

6. Grease Monkey => disabled, doesn't needed it anymore, but kept it installed, so that when i need to use it again, i can just enable it.

7. Memory Fox => i think i deleted this one, its useless.

8. Enhanced Steam => disabled, unless i want to look around on steam store, which i rarely do lately.

i think that's all.

if it wasn't because of lots of flashy flash based ads, i won't even need to use flash block, i really really hate flashy flash based ads.