Written by ways the 19 Sep 12 at 20:14.
I share a pretty new laptop (Core i3, 4GB RAM, SSD) with another person. We're both logged in, but have separate, logged in, accounts.
When I use the laptop her firefox processes (with flash and all) use a lot of system resources. Especially when I'm on battery and let laptop-mode-tools lower my systems performance things can get quite sluggish.
Just a note: unless you have swap, there won't be much you can do about RAM which I'm 95% is the resource you are actually running out of. If you DO have swap, the chances are the other user's memory is already being moved to swap, freeing up physical memory for you.