The benchmark is rather simple: they wrote a small .Net program called Memory Watcher which polls and graphs the memory usage of processes each 3 seconds. They then browsed the web with each browser for about 3 hours, recording memory usage as they went along. The results show a clear picture of which browser uses the least amount of memory.
Before we get to the results, I must make clear that the benchmark itself is heavily flawed, and that comparisons between browsers can not be made based on this benchmark. The 3 hour browsing session was not the same among the different browsers, and in fact, did not even last as long on all browsers. In addition, each session was different in that different websites were visited. Finally, the benchmark fails to mention detailed specifications of the test machine, other than that it has "3.0Gb+ of RAM".
Here are the results; the values between brackets are the memory used by the browser at the end of the browsing session (in MB):
- Safari 3.1 (636.9)
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 (111.8)
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.
- Flock (based on Firefox 2.0) (191.9)
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 (190.6)
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 (194.4)
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.
While the benchmark itself may not be very useful in inducing memory usage of browsers beyond this specific test, the graphs in the article do show a few interesting trends, and do provide a very rough insight into how browsers handle their memory.