Rated 3 out of 5 stars

Hi,
I don't know how much memory it does free, but
even after clicking the button, or opening about:memory and clicking "Minimize Memory Use", it gives this warning:
"WARNING: the following values are negative or unreasonably large.
explicit/gfx
explicit/gfx/heap-textures
explicit/(18 tiny)
explicit/(18 tiny)/heap-unclassified
This indicates a defect in one or more memory reporters. The invalid values are highlighted.
Explicit Allocations
410.39 MB (100.0%) -- explicit
├──4,083.59 MB (995.04%) -- gfx [?!] ------HERE
<<<<
│ ├──4,083.31 MB (994.98%) ── heap-textures [?!] <<<<
│ └──────0.28 MB (00.07%) ++ (5 tiny) "
and:
─-3,978.11 MB (-969.34%) -- (18 tiny) [?!] ------HERE
<<<<<
├───────3.80 MB (00.93%) ++ add-ons
├───────2.77 MB (00.67%) ++ cycle-collector
├───────2.76 MB (00.67%) ++ xpconnect
├───────2.57 MB (00.63%) ++ startup-cache
├───────2.55 MB (00.62%) ── spell-check
├───────1.09 MB (00.27%) ++ layout
├───────0.82 MB (00.20%) ++ network
├───────0.80 MB (00.20%) ── xpti-working-set
├───────0.67 MB (00.16%) ── cookie-service
├───────0.38 MB (00.09%) ++ dom
├───────0.37 MB (00.09%) ── preferences
├───────0.31 MB (00.08%) ++ xpcom
├───────0.27 MB (00.07%) ── telemetry
├───────0.24 MB (00.06%) ── icu
├───────0.13 MB (00.03%) ++ media
├───────0.10 MB (00.02%) ── script-namespace-manager
├───────0.01 MB (00.00%) ── history-links-hashtable
└──-3,997.74 MB (-974.12%) ── heap-unclassified [?!] -----HERE
I can send you the whole log if you want.
I'm using Ubuntu 14.04 Firefox 45.0.
Sorry to post this here but didn't see anywhere else.
Hope you can make it clear that too, cause I end up having to quit and restart firefox.
Thanks