Browser name Ending private set in MB
Firefox 3 111.8
Flock (Firefox 2) 191.9
Opera 9.5 190.6
Internet Explorer 194.4
These profiles are meant to provide a picture of what the memory behavior of popular browsers is over a period of time, not to provide absolute benchmark times. Firefox 3.0 shows memory usage that is significantly lower than Firefox 2, which also does very well. Here is a summary of my results.
* Safari 3.1
Safari on Windows shows extremely poor memory management, and I do not know whether it ever reaches a high water mark. If this is by design, it is certainly a design that looks inefficient and seems to contradict Apple's marketing.
* Firefox 3.0
This browser exhibits memory usage that is by far lower than the others. It releases memory to the system and the trend line is nearly flat.
(This is likely due to the efforts outlined here.)
* Flock (based on Firefox 2.0)
Flock did very well and this browser and Firefox 2.0 could likely be run for long periods without causing many problems. The extensions probably reduced the efficiency somewhat.
* Opera 9.5
Opera's performance was about as good as Firefox 2.0 (Flock), and it could likely be used for very lengthy sessions. However, Kestrel is certainly not a revolutionary or even notable technology in this arena.
* Internet Explorer 8 Beta 1
IE did well in the profile, although a worrying trend in the data could indicate that it would keep escalating. However, this browser could likely sustain many hours of moderate usage.