El Capitan iMac RAM usage

cbrand493

macrumors 6502
Original poster
May 19, 2015
335
242
Perth, Australia
Hi all,

I'm not sure if I have an issue here but I want other peoples opinions on this.

If I open every single app on my iMac, the max amount of ram I ever seem to use is 5GB out of 8GB total (according to Activity Monitor).

These apps include everything from Photoshop, Lightroom, Chrome, Matlab, Mathematica, the entire Microsoft Office Suite to the standard apple apps like pages, mail etc. I mean absolutely everything open at once. Yet I only use 5GB of ram? Does this seem right because in my mind applications like photoshop and lightroom alone should use that, let alone word/excel/outlook/powerpoint, matlab etc on top of that. Is my iMac writing the rest to my startup disk or is it actually using that little ram for so many apps?

System is a Late 2013 27" iMac w/ 8GB Ram running the latest El Cap beta. I'm on the fence on buying another 8GB and sticking it in there, so if it is writing to disk I'll bite the bullet however I don't want to waste money and find out I didn't need the extra ram.

Thanks

Edit: With very few apps open (chrome, finder & activity monitor) it uses 3.19GB. So running 20+ apps only uses an extra 1.8GB ram? BS.
 

chabig

macrumors 604
Sep 6, 2002
6,763
3,971
It sounds like you don't need more RAM if the applications you're using aren't demanding it. Your memory use shouldn't be determined so much by the number of applications you have open as much as it is by what you're asking them to do. An open but unused application shouldn't need much RAM at all, and the system won't allocate more RAM to it if it isn't asking for more RAM.
 

MacGizmo

macrumors 68000
Apr 27, 2003
1,661
982
Arizona
As @chabig has pointed out, you're not understanding how RAM and the OS work together. The OS will only use a tiny amount of RAM to keep an app open. Most of the RAM is dedicated to the app(s) you're actually doing something in at any given time.
 

dogslobber

macrumors 68040
Oct 19, 2014
3,873
5,862
Apple Campus, Cupertino CA
Hi all,

I'm not sure if I have an issue here but I want other peoples opinions on this.

If I open every single app on my iMac, the max amount of ram I ever seem to use is 5GB out of 8GB total (according to Activity Monitor).

These apps include everything from Photoshop, Lightroom, Chrome, Matlab, Mathematica, the entire Microsoft Office Suite to the standard apple apps like pages, mail etc. I mean absolutely everything open at once. Yet I only use 5GB of ram? Does this seem right because in my mind applications like photoshop and lightroom alone should use that, let alone word/excel/outlook/powerpoint, matlab etc on top of that. Is my iMac writing the rest to my startup disk or is it actually using that little ram for so many apps?

System is a Late 2013 27" iMac w/ 8GB Ram running the latest El Cap beta. I'm on the fence on buying another 8GB and sticking it in there, so if it is writing to disk I'll bite the bullet however I don't want to waste money and find out I didn't need the extra ram.

Thanks

Edit: With very few apps open (chrome, finder & activity monitor) it uses 3.19GB. So running 20+ apps only uses an extra 1.8GB ram? BS.
Can you post a snapshot of the Activity Monitor to see what you mean? A picture is worth 1024 words.
 

cbrand493

macrumors 6502
Original poster
May 19, 2015
335
242
Perth, Australia
This is the max I've ever seen it go no matter what I do. I've ran batch processing in Lightroom before and it's never gone above this. A mate of mine as a rMBP 13" with 8GB ram and his behaves the same. The only way he could push it above that was by running a Win 10 VM in parallels with 4GB RAM assigned to it.

I understand how ram works however ~25 apps (some big apps) using less than 2GB even at idle does not seem right.

Edit: checked the page ins for google chrome and they were into the hundreds of thousands. Lightroom was in the tens of thousands and so was photoshop. Most apps were in the thousands. Those page ins were just from idling newly opened apps.
 

Attachments

chabig

macrumors 604
Sep 6, 2002
6,763
3,971
That picture is not at all useful because it doesn't show the apps that are running and the memory they are using. You can't just show the total and expect to learn anything. It's the components of the total that are important.
 

chabig

macrumors 604
Sep 6, 2002
6,763
3,971
Thanks or the complete story. OS X is a well-architected, powerful OS. Pretty cool it can do that, no?
 

chabig

macrumors 604
Sep 6, 2002
6,763
3,971
Those apps aren't doing anything, so they don't require more than 25-75MB (MB!) each.
 

cbrand493

macrumors 6502
Original poster
May 19, 2015
335
242
Perth, Australia
Those apps aren't doing anything, so they don't require more than 25-75MB (MB!) each.
Then why does Lightroom have 122366 page ins if it's only requiring that much ram and there is 3GB free?

Edit: Photoshop has 86429 page ins, chrome 54231.

This is on a computer that's been booted, left with nothing running for a few mins to settle down, then opened every app. During the process of opening every app, at no point did the ram go above 5.19GB used. Yet all those page ins?
 
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