CCleaner loads slow when large Firefox cache

[WindHydra]

When loading ccleaner, there's high disk activity when firefox cache is large, even when I unchecked everything in the applications tab (seems like ccleaner still loads the directory structure from $mft). Is there a way to change this? Maybe a way to remove firefox from the applications tab?

[Andavari]

For the sake of curiosity how big is the Firefox cache?

 

You can decrease the cache size limit in Firefox if you've modified it to use a non-factory default amount, or have Firefox itself clean the cache when exiting it, maybe that would help.

[Winapp2.ini]

unable to recreate this using caches of 0.5-2.0Gb. FWIW I'm using the new cache backend though, so MMMV

[WindHydra]

It's set to auto, now using 400MB with 20k+ files. I think it's caused by loading the directory structure from MFT, because if I run folder properties on the cache folder before ccleaner, it loads a lot faster.

Clearing the cache works, but I want to keep the cache. If I move the cache folder away then run ccleaner, it's fast. But it's slow again if I move the folder back in.

 

What's the new cache backend? I tried adding browser.cache.use_new_backend in firefox 26 and it doesn't seem to work.

[Winapp2.ini]

The new cache back end is only in Firefox 28 and newer I think. 27 beta might have it but I don't recall