You didn't provide detailed configuration information...

In case one of your extensions is involved, could you test the page in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Diagnose Firefox issues using Troubleshoot Mode.

You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

Not all add-ons are disabled: Flash and other plugins still run

After Firefox shuts down, a small dialog should appear. Click "Start in Safe Mode" (not Reset).

Any difference?

Hi,

Sorry, I forgot to paste the support info.

Safe mode made no difference. Disabling Intel's processes from startup does seem to be helping, however.

{

 "application": {
   "name": "Firefox",
   "version": "31.0",
   "userAgent": "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0",
   "supportURL": "https://support.mozilla.org/1/firefox/31.0/WINNT/en-US/"
 },
 "crashes": {
   "submitted": [],
   "pending": 0
 },  "graphics": {
   "numTotalWindows": 1,
   "numAcceleratedWindows": 1,
   "windowLayerManagerType": "Direct3D 10",
   "windowLayerManagerRemote": false,
   "adapterDescription": "Intel(R) HD Graphics 4000 (Intel Corporation - WDDM 1.3)",
   "adapterVendorID": "0x8086",
   "adapterDeviceID": "0x0166",
   "adapterRAM": "Unknown",
   "adapterDrivers": "igdumdim64 igd10iumd64 igd10iumd64 igdumdim32 igd10iumd32 igd10iumd32",
   "driverVersion": "10.18.10.3262",
   "driverDate": "7-31-2013",
   "adapterDescription2": "",
   "adapterVendorID2": "",
   "adapterDeviceID2": "",
   "adapterRAM2": "",
   "adapterDrivers2": "",
   "driverVersion2": "",
   "driverDate2": "",
   "isGPU2Active": false,
   "direct2DEnabled": true,
   "directWriteEnabled": true,
   "directWriteVersion": "6.3.9600.17111",
   "webglRenderer": "Google Inc. -- ANGLE (Intel(R) HD Graphics 4000 (Intel Corporation - WDDM 1.3) Direct3D9Ex vs_3_0 ps_3_0)",
   "info": {
     "AzureCanvasBackend": "direct2d",
     "AzureSkiaAccelerated": 0,
     "AzureFallbackCanvasBackend": "cairo",
     "AzureContentBackend": "direct2d"
   }
 },
 "javaScript": {
   "incrementalGCEnabled": true
 },
 "accessibility": {
   "isActive": true,
   "forceDisabled": 0
 },
 "libraryVersions": {
   "NSPR": {
     "minVersion": "4.10.6",
     "version": "4.10.6"
   },
   "NSS": {
     "minVersion": "3.16.2 Basic ECC",
     "version": "3.16.2 Basic ECC"
   },
   "NSSUTIL": {
     "minVersion": "3.16.2",
     "version": "3.16.2"
   },
   "NSSSSL": {
     "minVersion": "3.16.2 Basic ECC",
     "version": "3.16.2 Basic ECC"
   },
   "NSSSMIME": {
     "minVersion": "3.16.2 Basic ECC",
     "version": "3.16.2 Basic ECC"
   }
 },
 "userJS": {
   "exists": false
 },
 "extensions": [
   {
     "name": "1Password",
     "version": "4.2.3.b1",
     "isActive": true,
     "id": "[email protected]"
   },
   {
     "name": "Adblock Plus",
     "version": "2.6.3",
     "isActive": true,
     "id": "{d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}"
   },
   {
     "name": "English (Australian) Dictionary",
     "version": "2.1.2",
     "isActive": true,
     "id": "[email protected]"
   }
 ],
 "experiments": []

}

To test how Firefox runs "uncustomized" on your system, could you do a two-minute experiment?

Create a new Firefox profile

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should have completely fresh settings databases and a fresh cache folder. Except for not having any pages cached, it should perform as well as can be expected.

Exit Firefox and start up in the Profile Manager using "Run" from the program list or you may be able to use the charms bar search box:

firefox.exe -P

Don't delete anything...

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button and name it something like TEST, then skip the option to change the folder location. Then start Firefox in the new TEST profile.

Any noticeable difference in performance?

When returning to the Profile Manager, you might be tempted to use the Delete Profile button on TEST. But... it's a bit too easy to accidentally delete your "real" profile, so I recommend resisting the temptation. If you do want to clean up later, I suggest making a backup of all your profiles first in case something were to go wrong.

I've mentioned this a couple of times, but I saw improved performance simply by disabling Intel's graphics processes :)

I'll do this if I see it happening again even with those disabled.

Okay, I thought you still wanted help. My mistake.

Apologies, I didn't meant that I don't appreciate your help. I just wasn't quite sure where to post this. I can't seem to find any references in Bugzilla to Intel's utilities causing issues with Firefox.

This is the closest that I can find. I'll try to disable hardware acceleration next time. https://bugzilla.mozilla.org/show_bug.cgi?id=823954

OK, I tried a new profile and it's MUCH better (but I didn't open all of my pinned tabs). I'll try that next.

I nuked my profile using the about:support page and re-generated it. It seems to be a LOT better now.