TheT3: Which one uses the least amount of memory when in operation?
AndrewC: Depends on your usecase; I usually get Firefox 4 to around 400+ MB of RAM but that's with a heck of a lot of tabs open (around 60) and some of them filled with flash and other intensive things.
If I try to do the same with Chrome it crashes at around 30 tabs (not to mention that i can't see the titles of the tabs anymore).
I haven't tried this yet with IE9 but I guess it would behave nicely. It seems that so far it uses the least amount of memory in light use when compared to FF or Chrome.
That's true, I tend to have a moderate number of tabs open at any given time and I'm probably more similar to normal people. But, what you're describing isn't surprising, one of the side effects of creating an entirely new browser process for each tab is that you're going to waste a lot of memory on a normal operational basis.
It'll be interesting to see how much memory Firefox uses when they finish the process of creating separate processes for tabs, since they're planning to limit that primarily to the rendering and specifics of the page.