Applications on Mac use up a lot more memory than on Windows

Somewhat.

Mac OS X gives programs as much memory as is possible when it's free, and scales back when RAM starts to get in short supply.

In general, Windows has always been notoriously dishonest and horrible when tracking memory usage. Part of it comes from the page file--when Windows swaps memory from ram to the page file, it "no longer considers it in memory" anymore. Macs are more honest and vigorous in tracking memory usage (the unix connection). So, it's not the Windows programs use less memory, it's that Windows doesn't track it as well. This is also another reason why it's often harder to recover from Windows crashes than Mac crashes. Both platforms have protected space, but since Macs are better and blueprinting it, it's easier to recover from it.

Interesting. Is this why my VM size is 8.26Gb when there's 1.38Gb RAM free?
I'm not being narky, just don't understand why the VM is soooo fat, free mem is huge and I still get beachballs!

windows' memory management has been designed back in 80's when memory was expensive. (anybody here who had +16MB before 90's??) the great thing back then was the idea of flushing all data that has not been touched for 15 minutes into a swap file - the slower memory - and to offer some free memory for apps that the user may want to open next. it was nice back then, but it's not nice at all that microsoft has not changed the way windows behaves now that some rich jackass may install +16GB into a box that runs windows.

in other words, windows takes memory away from the present apps and wishes that user wants to open more apps in the future. unix does it differently, it focuses on what the system is doing CURRENTLY, which is what the user always does too 😉

Well, let me put a quarter in the bucket <let me add some>

Unix like OSes <OS X>, just use all the phisical memory <RAM>

So -theoretically- if you start 1 app, and let it run for ages, it is feasable that the entire memory would be filled with this single app.

Which for a windows user is a bad thing, because, as experience taught us, when a program starts eating memory a crash is imminent, either of the app or the OS....

A healthy unix system has very very little empty memory, and a lot of inactive but used.

Now if you would start a second app, then the OS descides that the first app has to give some of it's memory back, preferbly inactive memory.

And the two apps start sharing ALL the memory...

Now, we all know, there are dozens and problably hunderds of little apps using a bit CPU and a bit Memory... but the idea is the same.

Minimise unused memory and redistribute inactive memory for new apps <or apps which need more>

There are a lot of technical remarks to be made about the above explanation, but i believe the bottom line is correct.

ShopJockey said:

I'm not being narky, just don't understand why the VM is soooo fat, free mem is huge and I still get beachballs!

Click to expand...

The explanations here pretty much get the point across, but in answer to your beachball question, it's likely that they're due to something unrelated to memory--there are plenty of other things that can cause temporary beachballs, and based on experience (thought dependent entirely on what you're doing), I'd say heavy disk use followed by heavy processor use are the most common causes. Running with 2.5GB of RAM, low memory is rarely the cause of any pauses for me, but that doesn't mean I don't see them periodically.

Also remember that you can usually work in another app if one app has paused on a beachball to do something--I frequently do this while doing large operations. The only thing I've noticed that will beachball the whole system is stalled disk access (while a drive spins up or a network volume becomes available)