[kevs]

Wondering if someone could go over the activity monitor.

Specifically, free, and used. Are these the things to look out for, in evaluating if you have enough Ram?

Also, I was burning a DVD with Toast today, and Toast was not listed, but at the top it said "window server" twice, both at 22% CPU. Was that Toast?

thanks!

[Tyler McAdams]

I personally do not use the "activity monitor" but I do have a pretty good knowledge of other UNIX on the market like AIX, IRIX, and Solaris. AIX has an application that is usually installed on the server versions called "monitor". Monitor has also survived in OS X by an application that is a spitting image of it called "aquamon"

http://www.macupdate.com/info.php/id/7583

Aquamon will keep track of all virtual memory and physical memory usage, and in my opinion, is the best app for OS X to monitor it from. "Top" and "vmstat" work ok but can be confusing at times... once again I've only used the Activity Monitor a handful of times.

To answer a part of a question you asked earlier in your other thread about VM being a part of OS 9... VM is not a "bad" thing that somehow made it to OS X. VM is a part of every major OS out there and is really a good thing. The problem OS 9 had that had issues *with* VM was that the multitasking envoirnment did not have a mature VM managment policy. OS 9 had what is called a cooperative multitasking enviornment where as OS X has what most well written OSes have today which is preemptive multitasking enviornments... OS X gets it's VM managment from UNIX derivatives which are all top notch facilities. Bad VM management of OS 9 casued all sorts of issues like overwriting system or program memory address space with temporary data... this in most basic terms crashed the entire OS and made you have to restart the system. This VM managment was bad but alot of the "snappyness" of OS 9 can be attributed to it... it's a bit of a double edged sword, but for me, and most everybody I imagine, would trade that up any day for an OS that is actually stable enough to get some real work done on it.

Using Aquamon or activity monitor will give you all the details of what's being paged out, but the truth is that you will be able to actually tell when you've hit the swap because the entire operation you were doing will come to a halt and crawl to completion. This will be evident in Photoshop when something that usually takes just a small amount of time starts taking a ton of time. Disk paging is several orders of magnitude slower than ram memory so that's how you can tell. Any big file you're working with has the potential for this so you might want to check the size of the file first before working on it to see if you have enough memory... if all your files are like this you need more ram.

So I would use aquamon too and also read the following article to make sure you have a good knowledge of what exacltly is going on with the memory subsystems concerning handling onscreen data and other related issues that can affect perfomance:
http://arstechnica.com/reviews/02q3/...sx-10.2-8.html

Also you had mentioned that you had hid an application from the screen and still saw it in memory... Hidding the app only removed the data *on screen*.. the application is still in memory however... only now you just can't see it. This hidding function only servers to simplify your veiw of what you're working with on your screen... it does nothing to the actual program in memory such as killing it. To take a program out of memory you have to completely exit out and quit the program.

[Tyler McAdams]

Another program you might want is called "diskspy".
http://seiryu.home.comcast.net/diskspy.html

Diskspy sits in your top menubar and will give a green or red light when your disk is being wrttten or read from... you will be able to tell the exact second your system starts paging out with this small app graphically.

[Tyler McAdams]

A little more reading makes me think I was right about the system cache clearing at reboot also... or the "Buffer Cache" as the arstechinca article put's it:

http://arstechnica.com/reviews/01q4/...html#vm-basics
"The Buffer Cache

The second most important factor in Mac OS X's memory usage behavior is the buffer cache. The buffer cache is meant to speed up access to files on disk. Every time a piece of data is read from the disk, it may (optionally) be stored in memory. If that same piece of data is needed again in the near future, it may still be available in (physical) memory, saving a trip to the disk. Mac OS X implements a "unified buffer cache", meaning that the buffer cache and the virtual memory system are combined. A page is a page is a page in Mac OS X.

The buffer cache affects RAM usage in ways that a Mac user may not expect. Heavy file i/o can use a lot of physical memory very quickly, potentially thinning out the physical memory presence of running applications. Poorly written applications may exacerbate this problem by using cached file i/o when it is not necessary, or even useful. An application that reads and parses a large file a single time during start-up should probably not use caching i/o, since it is not likely that the application will need those memory pages again some time in the near future before they're evicted from physical memory by another active process."

Since the buffer cache and memory system are combined this is more than likely the reason you're coming back to your computer and seeing the slow down... because the applications you've been using are in the buffer cache and have been paged out to disk... all that info being pulled from disk is causing the slowdown and since you reboot it's cleared and now everythig is loaded in to memory.