I've an old PC (Dell Optiplex GX50) with an Intel Pentium III CPU @768Mhz and 256MB of RAM, with Windows XP. When I booted it yesterday, Firefox 3 was installed (and nothing else). Openning 2 tabs (Youtube main page, Google), it was consumming around 60-70MB of RAM. Now I installed Firefox 27, and it is consumming 140MB of RAM with the same 2 pages loaded. With Firefox 3, I was able to load several tabs, around 15-20 and it started to slow down. Now a few tabs and it consumes all the RAM.
Why, from Firefox 3 to Firefox 27, RAM consumption has doubled without using any special functionnality and only loading 2 pages ? I know there were many new functionnalities added, but here I'm not using anything special. Mozilla also stated they were trying their best to limit RAM consumption. (as we all know since Firefox 4 it has increased much).
So, how to limit RAM consumption on this old PC ? Is there a way to disable unused functionnality, and which are those ?