Is your Firefox up-to-date?
Originally Posted by BDSandM
Even on my shltty computer it was fast as fvck, while IE and Firefox were baby-speeds.
Chrome is more efficient since it only initially uses about 175 MB of RAM, but every time you open a new tab another background process is created which takes about 15-20 MB of RAM. Nor are these processes ended when the respective tab is closed, so you can very easily accumulate quite a few additions. I've had Chrome run upwards of 400 MB total, when Firefox doesn't use more than 300.
Really I would recommend any browser except for maybe Safari as I don't like Apple as a software company. Internet Explorer (9 works very well), Firefox, Chrome, or Opera are all perfectly good choices.