Safari RAM usage

[OldCorpse]

I'm a complete Mac newbie... just 6 days... I opened my activity monitor for the first time, and I noticed that Safari is taking 135MB... now, I have only one window open and no extra tabs, I'm not downloading anything... in fact, I'm simply open on the macrumors forums... 135MB of RAM seems a bit high, doesn't it? So, I did a test... I just let the computer sit - jiggling the keys from time to time to prevent sleep - did this for about 10 minutes while reading a book, not using any resources on the computer... I click on activity monitor, and it's still showing 135MB RAM used by Safari... is this normal? If it is, I guess it's a good thing I decided to get 1.5GB of RAM, otherwise with Safari just open passively on one page, one window, no tabs and I would hardly get to do anything else for lack of memory TIA

Edit: I quit that one window in Safari, it went from 135MB to 130MB... that's with no windows! So I quit Safari altogether. Then, I open it up again, it brings me one window with my home page, and now the activity monitor is showing 15MB used... what's going on?! Does Safari slowly eat memory after a few hours?

Edit 2: So, immediately after I opened Safari it was at 15MB... I write the edit above, post it, and check activity monitor, it's now up to 22MB... wow, that's fast! Does it mean that if I use it long enough it'll eat all the memory and freeze? Or maybe freeze the whole computer with an "out of memory" message? And I'm not even doing anything intense like playing audio/video files in the browser, or downloading or displaying a whole bunch of scripts... hmm...

 

[mad jew]

Okay, well RAM allocation in OSX is complicated and convoluted at best but I'll try to explain what I know at best.

OSX will allocate memory to an app (like Safari) and not necessarily use it. Whilst Safari claims to be using 135MB, all that means is that at some stage it has used 135MB and the surplus (the difference between what it was using and what it now uses) has not yet been reallocated to a different process or app. In other words, unless OSX needs that RAM back, it'll continue to allocate it to Safari irrespective of whether it's being used. I may have this wrong (because I am mad) but it's the best attempt I can summon on this barmy summer's night. Did any of that make sense?

My advice is to not worry about it unless you notice that the computer is running slowly when it shouldn't be.

 

[OldCorpse]

Thanks, mad jew, I guess that makes sense... I'm still amazed that Safari can use 135MB at any point... all I was doing is surfing, no video or music or heavy flash/script sites. Oh well.