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2012Tony2012

macrumors 6502a
Original poster
Dec 2, 2012
741
3
No, your problem is that you do not use the right tools (i.e. enough RAM) for your tasks. Why should we think, that the OS X is responsible for your problems?

If you buy a slow car, you cannot expect a Ferrari. My advice is: Buy the right tools (RAM upgrades or computers, if you can) for your tasks. It is really not difficult.

You are WAY OF TRACK and your comments are completely irrelevant! It's obvious you have not read or understood my comments. My iMac runs FAST and SMOOTH, let's repeat...it runs FAST AND SMOOTH! You need to read and maybe get someone to explain to you my comments as to the issue.

And once again, another very poor analogy that does not apply to me and my situation.
 

smithrh

macrumors 68030
Feb 28, 2009
2,722
1,730
To the OP:

I know this sounds far-fetched, but to reclaim your inactive RAM, use "Repair Disk Permissions" in Disk Utility. Try it, you'll see. The downside to this is that it can take anywhere from a couple of minutes to 5-6 minutes to complete. But it will save you a reboot.

To the others:

* 'purge' only exists on systems that have the Developer tools installed.

* There *are* instances where Mac OS X will page out when there is no free RAM but gobs of inactive RAM, leading to horrible performance.

* If you personally haven't seen this behavior (I have), then you really shouldn't dismiss it out of hand.

* One should note that Apple is pouring a lot of effort into improved memory management in Mavericks. Now, why would this be if things were in such a wonderful state presently?

* Apple also made improvements to memory management in 10.8.

So, yes, we've been over this before, mainly because some people don't like to listen. There are problems with memory management in OS X. If you haven't run into them, congratulations.

But that doesn't mean problems don't exist.
 

AnonMac50

macrumors 68000
Mar 24, 2010
1,577
323
To the OP:

I know this sounds far-fetched, but to reclaim your inactive RAM, use "Repair Disk Permissions" in Disk Utility. Try it, you'll see. The downside to this is that it can take anywhere from a couple of minutes to 5-6 minutes to complete. But it will save you a reboot.

To the others:

* 'purge' only exists on systems that have the Developer tools installed.

* There *are* instances where Mac OS X will page out when there is no free RAM but gobs of inactive RAM, leading to horrible performance.

* If you personally haven't seen this behavior (I have), then you really shouldn't dismiss it out of hand.

* One should note that Apple is pouring a lot of effort into improved memory management in Mavericks. Now, why would this be if things were in such a wonderful state presently?

* Apple also made improvements to memory management in 10.8.

So, yes, we've been over this before, mainly because some people don't like to listen. There are problems with memory management in OS X. If you haven't run into them, congratulations.

But that doesn't mean problems don't exist.

So that's why purge wouldn't work on m iBook. Thank you.
 

benwiggy

macrumors 68020
Jun 15, 2012
2,371
179
I know this sounds far-fetched, but to reclaim your inactive RAM, use "Repair Disk Permissions" in Disk Utility. Try it, you'll see. The downside to this is that it can take anywhere from a couple of minutes to 5-6 minutes to complete. But it will save you a reboot.
Yep, sounds far-fetched to me. :p
Can you cite any information showing any relationship between memory usage and repairing permissions, which does very little at the best of times?

I'm going to need some evidence beyond "I repaired permissions and then things got better -- the two must be connected."
 

smithrh

macrumors 68030
Feb 28, 2009
2,722
1,730
Yep, sounds far-fetched to me. :p
Can you cite any information showing any relationship between memory usage and repairing permissions, which does very little at the best of times?

I'm going to need some evidence beyond "I repaired permissions and then things got better -- the two must be connected."

The cool thing here is that you need not believe me - you can try it for yourself.

Easy test plan:

* Get your Mac into a state where there's a lot of inactive RAM usage

* Run "repair disk permissions" from Disk Utility

* Watch your inactive RAM usage drop while repairing permissions works

When the repairing is complete, you'll have no or very little inactive RAM usage.


Update: interestingly enough, in 10.8.4 this no longer has any impact on inactive RAM, at least on the one Mac I tried it on. I don't have any machines on SL so I'm unable to run it on a SL machine.

It doesn't have to be Disk Utility either, you can get the same result from du -t / if run as root, but Disk Utility doesn't require root password.
 
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benwiggy

macrumors 68020
Jun 15, 2012
2,371
179
* Run "repair disk permissions" from Disk Utility
* Watch your inactive RAM usage drop while repairing permissions works

Update: interestingly enough, in 10.8.4 this no longer has any impact on inactive RAM, at least on the one Mac I tried it on.
So, what you're saying is: Inactive RAM is freed up when a resource-intensive task is performed?

Sounds like OS X memory management is working well!
 

throAU

macrumors G3
Feb 13, 2012
8,772
6,935
Perth, Western Australia
(from experience with pretty much every OS out there)


Memory management in Lion was a bit borked. It was doing the right thing, but tuned to be too aggressive in terms of balancing between purging and paging for a spinning disk. On SSD (which is what I guess the mac developers were running it on :D) it was fine. If you had 8 gigs it was a lot better. I.e., the theory was sound, the tuning knobs were set wrong.

10.7.4 and ML fixed that to an extent. Mavericks is better. I've run all of them on the same hardware.


SL doesn't suffer from the same problem (which runs happily on my mini with 2 GB, but doesn't do any iCloud stuff, doesn't do versions, etc, etc.... features aren't free and RAM is cheap. buy more!)



edit:
"repair disk permissions" is just flushing inactive memory by making the OS demand ram for disk cache (and it will be forced to drop inactive content to satisfy that). the time you spend rooting around with disk utility could be better spent just waiting for the machine to swap stuff back in that you're actually working on.

but yes, the process you are following WILL do something similar to purge. sort of.
 
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smithrh

macrumors 68030
Feb 28, 2009
2,722
1,730
So, what you're saying is: Inactive RAM is freed up when a resource-intensive task is performed?

Sounds like OS X memory management is working well!

No, hardly.

'du' doesn't qualify as any sort of resource-intensive task.

Nor does 'repair_packages'.

To be clear, this trick has been around for quite some time, I'm certainly not the first to use it:

https://forums.macrumors.com/posts/1584691/

----------

the time you spend rooting around with disk utility could be better spent just waiting for the machine to swap stuff back in that you're actually working on.

The problem - and I'm really hoping 10.8.4 has fixed this, but we'll see, plus this is a SL thread - is that swapping occurs when there is gobs of inactive memory available.

I don't give a flying hoot about things happening that don't impact performance - rather, this is a problem that would cause bad performance, then I went looking for the cause.

Now I'm nearly 100% SSD on my Macs, still see the problem from time to time but now a reboot is fairly painless to execute.
 

2012Tony2012

macrumors 6502a
Original poster
Dec 2, 2012
741
3
.... and I'm really hoping 10.8.4 has fixed this, but we'll see, ...

Don't hold your breath...if they couldn't be bothered to fix this so far, then they probably never will. It's a VERY POOR design FLAW in Mac OS X.
 
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