For all Moz user ..... "Mozilla has improved Firefox's memory usage significantly in recent time. Many Internet users still think that Firefox is using a lot of memory, but if you compare actual memory usage between different browsers, you will notice that Firefox's memory handling is excellent.
That does not mean that you may not see spikes in memory usage even if you open the same websites as someone else. One of the reasons for this discrepancy in memory usage are add-ons." .... [ »
www.ghacks.net/2014/05/1 ··· -reason/ ]