[llambda]

I'm actually continually amazed that even some technically inclined people misunderstand how memory works in /all/ modern OSes: recently I had a discussion on Twitter that went something like this: "OS X is horrible, it uses nearly all of my 8 gigs of RAM and my browser is horribly slow!" to which I replied, "it's perfectly normal for the OS to appropriate the RAM in the fashion you see in Activity Monitor; this doesn't mean your machine is slow due to lack of RAM." Unfortunately, even after a lengthy discussion and several forwarded links, I seem to have failed to make the case.

It would be interesting if someone more knowledgeable than I am were to do a write up explaining memory usage in OS X, Windows, and Linux; would be an awesome resource to share with curious tinkers who may be slightly misguided in their understandings of the inner-workers of their computers.

[evmar]

Probably more technical than what you wanted, but here's a bit about how memory works from the "how much memory is the app really using" perspective.

http://neugierig.org/software/blog/2011/05/memory.html

[flomo]

On a few occasions, Safari has claimed gigabytes of memory and caused my machine to start thrashing the swap. In that case, the correct answer is to restart Safari, not take a refresher course on virtual memory allocation.

Windows Vista had an issue where copying large files would set off such a huge swap-storm that OS became completely unresponsive for several minutes. People gave all the same VM excuses then as well, but there obviously was something wrong.

[scott_s]

Those aren't excuses, those are reasons: copying large files are the pathological case for just about all caching techniques. You've now kicked out everything useful from your cache with something that you will never use again. It has little to do with virtual memory itself.

[njloof]

As for why the browser is horribly slow, try blocking all the unnecessary (read: tracking) Javascript and Flash. Suddenly, the browser is a joy to use again.