inactive RAM, free RAM, and page-outs

lord patton

macrumors 65816
Original poster
Jun 6, 2005
1,050
4
Chicago
Is inactive RAM supposed to be used by the system before relying on page-outs?

The reason I ask, is I just did some Photoshop Elements stuff, really just cropping, cutting, and pasting (although I did put some largish things on the clipboard in the process).

I used activity monitor to watch what was happening. The free RAM went to 10-20 MB, the page-outs went up by the tens of thousands, and the inactive RAM stayed around 200 MB.

I know I should max my PB RAM to 1.25 (it is currently 768), but don't want to drop the bread on it right now. In the meantime, is everything working as well as it could? It seems to to me (and I don't know) that the system should grab that inactive RAM first.

any help?
 

Eniregnat

macrumors 68000
Jan 22, 2003
1,841
0
In your head.
This is not odd. This Apple article does the process little justice. There are a few things to keep in mind. Since page-in/outs is about using virtual memory on the RAM disk, you know that more memory would reduce this number some. But what isn't often thought of is that sometimes applications reserve RAM, and some applications like Adobe applications, manage their applications processing memory differently. For short processing tasks, inactive RAM may not be grabbed. It may have been cached to the disk (page in) but for speed it isn't being cleared and reclaimed. One way to minimize this is to not run Dashboard, Safri or other applications at the same time you run a media editing application. Apple is running really good memory management routeens with OS X. It seems to get better with every major revision.

As a side note, Adobe's scratch is your disk, your computer's VM is on the disk, and your source data and application data is on the disk. This is not optimal for doing media editing (still image, audio, and video) all benefit from having Adobe's scratch set elsewhere. I'm running on older licences for Photoshop, Illustrator, and FCP, so perhaps things have changed.
 

superbovine

macrumors 68030
Nov 7, 2003
2,872
0
lord patton said:
Is inactive RAM supposed to be used by the system before relying on page-outs?

The reason I ask, is I just did some Photoshop Elements stuff, really just cropping, cutting, and pasting (although I did put some largish things on the clipboard in the process).

I used activity monitor to watch what was happening. The free RAM went to 10-20 MB, the page-outs went up by the tens of thousands, and the inactive RAM stayed around 200 MB.

I know I should max my PB RAM to 1.25 (it is currently 768), but don't want to drop the bread on it right now. In the meantime, is everything working as well as it could? It seems to to me (and I don't know) that the system should grab that inactive RAM first.

any help?
the money you speed for 1gb would be well worth it. as to you question, the schemes that operating system in general that decide what should be swapped to ram or hd is a bit complex to explain. just know that, that it is made to be efficient in general, but different operating system take different approaches so you might see different reaction between a windows pc with the same about ram and a mac.
 

lord patton

macrumors 65816
Original poster
Jun 6, 2005
1,050
4
Chicago
thanks all.

I'll spare you the affront of asking where to buy the ram and just go search the forum. I love this place.