[Daryl]

Hi

On my imac running Mac OS 8.6,
with Virtual Memory On, using My Settings
in the Extensions Manager,
the System uses 19-20mb of memory.
How does Mac OS 9 compare for users who have used both it and recent previous versions of the Mac OS

Daryl

[dbergstrom]

There's some discussion of this in the Performance of OS9 topic, but in general it appears to be using 5-10 MB more memory than OS8.6. On my Wallstreet 233 with virtual memory off and 160MB of RAM, it has used as musch as 57MB (when I have lots of applications open).

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Don

The amount of RAM your system will use depends on what extensions you're loading amongst other things. I, for instance, don't have many extensions loading and am able to run 9 on a 9500/120 w/32MB of RAM. The OS is only taking 15MB of RAM with VM turned on(the system automatically set VM to 64MB). Since loading this on the machine, I've been able to play MP3s with Quicktime player without any skipping while the finder carries out its processes. Apps don't take as long to launch, etc. The system just seems a lot more responsive versus 8.6. Moral of story: Play around with it. Create extension sets that work best with the way you work.

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"Anyone up for naked baby oil Twister?!"

[shua]

Just installed OS 9 two days ago... memory jumped about 7-8 mb. The issue I have is that on my BW G3 with 128mb ram, I have to restart the finder about once an hour to free up memory.

Anyone else?

There are a few things to note here.

On my Wallstreet 233 with virtual memory off and 160MB of RAM, it has used as musch as 57MB (when I have lots of applications open)

Don't confuse the Mac OS and Finder RAM requirements with dymanically loading shared libraries. As you open more applications, some of them load shared libraries, which tend to show up under the "Mac OS" memory area. Where are you getting 57MB from, BTW?

Also, Shared Libraries are designed to reduce memory consumption, as there is less duplicate code loaded in memory.

The issue I have is that on my BW G3 with 128mb ram, I have to restart the finder about once an hour to free up memory.

There have been some covert changes to Mac OS memory management as of late. For example, say the Finder claims that the "Largest Unused Block" is 60MB. And after you quit Netscape, that number stays the same -- 60MB. You may think that you "lost" 8MB somewhere, but in fact, if you relaunch Netscape, you will likely is still at 60MB, or just a tad less.

While I have seen no official documentation on this, it appears that application memory is not immediately released, but is available nonetheless. The "About This Computer" dialog doesn't always seem to tell the whole story.

Of course, use this information in conjunction with the understanding that you should launcing your most frequently used applications first (mail/web clients), and launch other things afterwards. Whenever possible, quit applications in the reverse order that you launched them to reclaim their memory. For example, if you launched Photoshop last, quit it first when you need more memory. You don't have to do this, things will probably just work better if you do.

Yes, it's unfortunate that this is the way Mac OS memory management currently works. Windows 95/98 has this problem as well, but to a far lesser degree (I don't really know about NT). Unix doesn't. Fortunately, Apple has come up with some clever tricks (like the one noted above) to temporarily deal with the problem until Mac OS X is out.


If you insist on force quitting the Finder (which does, in fact, seem to solve this problem), I recommend you write an AppleScript that does it, and only run the script when there are no other applications running. Force-quitting anything on a regular basis is a really bad idea.

- Scott

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Scott Stevenson
Contributing Editor,
MacNN



[This message has been edited by scott (edited 10-23-1999).]

[Burpethead]

I have a iMac 233 with 160 megs of RAM running OS 9f9 with lots of extensions and it takes 54 megs, the same as OS 8.6 for me

[Josuah]

There have been some covert changes to Mac OS memory management as of late. For example, say the Finder claims that the "Largest Unused Block" is 60MB. And after you quit Netscape, that number stays the same -- 60MB. You may think that you "lost" 8MB somewhere, but in fact, if you relaunch Netscape, you will likely is still at 60MB, or just a tad less.

While I have seen no official documentation on this, it appears that application memory is not immediately released, but is available nonetheless.

Largest Unused Block means exactly that, the largest unused block of memory. In other words, if you load up the Finder, then Navigator, then launch Calculator, quitting Navigator is not likely to increase the largest unused block. Instead, you'll have a fragmentation like this:

[Finder|Navigator|Calculator|Unused]
-> Quit Navigator
[Finder|Unused|Calculator|Unused]

If it happens that the second unused portion is 80 MB, while the first unused portion is 32 MB, you have 112 MB unused but the largest unused block (and therefore the largest amount of memory you can allocate to an app) is 80 MB.

[This message has been edited by Josuah (edited 10-24-1999).]

[shua]

Finders Friend has been an extremely useful Applescript finder utility!

[Don Foy]

How much memory does Mac OS 9 use?

It's kind of like a Democratic Tax Form I saw once.

How much do you have?

Send it in.

How much memory does Mac OS 9 use?

How much do you have?

[wlonh]

Don Foy is correct to certain extent... lol

And I have noticed Netscape does not give up its RAM allocation after quitting, AT LEAST it does not show in the About This Computer... and yes I have read the above posts and have a grasp of the situation... indeed the RAM is available even though Netscape "didn't give it up"...

But it just peeves me that Netscape can't do what every other app on my Mac CAN and DOES: give up its RAM allocation FOR REAL once you quit it/them! Including IE 4.5. My dislike of Netscape knows no bounds.

and remember folks, 64M of RAM ain't nothing these days, a good starting point is 128M...

and Finder's Friend is great, been using it for sometime because of (cue sinister music) Netscape! find it at www.versiontracker.com

[This message has been edited by wlonh (edited 10-25-1999).]