04-18-2012, 12:29 PM

At boot, my RAM's usually 1/4 full. okay, that's not bad. But it seems like it gets used up fairly quickly. A big culprit I know is with my Chrome use, but even then I don't feel like I'm doing anything hardware intensive, and when I close all my programs the RAM still settles down to over half used. Is this fairly normal?

I've attached a screenshot with the programs I have running.

04-18-2012, 12:39 PM

I don't see anything unusual there other than the excessive amount of data paged in. Out of curiosity, how often do you reboot?

Clearly, something is amiss. Chrome does use quite a bit of memory but not to the point where it causes problems (especially since you have 3+ GB of RAM). Thus, something else is consuming quite a bit of memory. Next time you see massive drops, take a look at AM and find the culprit.

04-18-2012, 12:47 PM

Usually I see shockwave and the chrome renderer taking up the most space, as well as chrome itself. I guess everything is normal. It's just I've never noticed a lack of RAM in the past before I started using Mac OS (~2 years ago).

I probably reboot once a week, when I feel it's too sluggish and when I have the patience lol

btw, what does the paged in portion mean?

04-18-2012, 01:04 PM

Paging is a bit complicated and I fear that my lack of understanding with regards to the specifics will complicate things if I try to explain it. You can read up on paging here. I do know however that excessive paging is reflective of a continual lack of RAM.

04-18-2012, 01:18 PM

From my understanding..."Page Outs" is the more important number. As the "page-out" number grows..more & more info is shuttled to/from the hard drive...slowing things down (since accessing the hard drive for info is MUCH MUCH slower than ram).

Ideally (with enough installed ram) "page-outs" can/will be zero (initially after reboot.and for a long period after rebooting). But even if lots of ram is installed...and the computer is used for long time (weeks) without a reboot...eventually page-outs will grow from zero....and grow & grow & grow.

This is why rebooting the computer every so often can be helpful. The less installed ram...the more frequent reboots should be. What is "frequent"...depends on the user. Basically a user should monitor their computers "page-outs"...and when the computer seems to be getting slow...reboot.

The size of the page-outs I believe can also be effected by how many apps. someone opens/uses simultaneously. So a BAD combination (from a page-outs and slowness perspective) would be to:

- not have much installed ram (for example 2 gig)
- open lots of apps. (let's say 5+)
- use the computer a lot (4+ hours/day)
- don't reboot often (say weeks between reboots)

...this would be a formula for a REALLY slow computer, with a LARGE amount of "page-outs"...and possibly lots of "beachballing".

- Nick

p.s. Read the link in my signature "Beachballs"...there's some good links in there as well!

04-18-2012, 01:27 PM

I think you're probably right - page outs would be the more problematic figure (this logically makes sense). Does paging in then happen anytime something is loaded into memory? Honestly, paging is completely foreign to me, haha.

04-18-2012, 01:38 PM

Originally Posted by vansmith

I think you're probably right - page outs would be the more problematic figure (this logically makes sense). Does paging in then happen anytime something is loaded into memory? Honestly, paging is completely foreign to me, haha.

Here's the way I understand it...

If an application calls a "page" and it is in RAM, then it is a "page in". If an app calls for a page, and that page is currently stored on the hard drive (and has to be read back into the RAM), then a "Page Out" occurs.

So the "in" or "out" terminology I believe refers to whether the info is stored "in" the ram...or "out" of the ram.

Thus "page-outs" are very slow due to the transfer of info from the HD back into ram.

- Nick

04-18-2012, 01:58 PM

I'm going to steal the Wikipedia definition for a moment:

Page in is transferring a page from the disk to RAM. Page out is transferring a page from RAM to the disk

As I understand that, both would be throttled by the speed of the hard disk no?

04-18-2012, 02:28 PM

Originally Posted by vansmith

I'm going to steal the Wikipedia definition for a moment:As I understand that, both would be throttled by the speed of the hard disk no?

Yes...I misspoke regarding "page-in's". I saw the same definition for "page-ins" in other links as well.

Here's an Apple link which tries to explain things:

Using Activity Monitor to read System Memory and determine how much RAM is being used

...and here's a quote from the "page in/page out" section:

Page ins/page outs:

"This refers to the amount of information moved between RAM and the Mac's drive. This number is a cumulative amount of data that Mac OS X has moved between RAM and the Mac's drive.

Tip: Page outs occur when the Mac has to write information from RAM to the hard drive (because RAM is full). Adding more RAM may reduce page outs."

Here's another good link explaining Macintosh ram usage:

Does my mac need more memory?

And a quote from it regarding page outs:

"A Page out means your computer has run out of memory and had to use some of the Hard Disk instead of RAM. This DRAMATICALLY slows down your computer."

The bottom line seems to be (from all of the research I have done)...is that "page outs" seem to be much more important than "page ins". And having a lot of page outs pretty much means that the computer needs more ram.

What is a lot of "page outs"? I've seen links state that if the "page-out" value represents more than 10-20% of the "page-in" value...more ram is suggested/needed.

- Nick

04-18-2012, 02:42 PM

Thanks for the clarification. It would seem then that a page in would be the transfer of content from the hard drive into memory. Since the value is so much greater, does that include application execution?

04-18-2012, 03:22 PM

Originally Posted by vansmith

Thanks for the clarification. It would seem then that a page in would be the transfer of content from the hard drive into memory. Since the value is so much greater, does that include application execution?

I think that we're getting pretty "deep" here!...so I'm not 100% sure.

According the the Apple definition of "page-in/page-out":

"This refers to the amount of information moved between RAM and the Mac's drive. This number is a cumulative amount of data that Mac OS X has moved between RAM and the Mac's drive."

So using that info...I'm thinking that the page-in/page-out numbers simply represent the amount of info that is being transferred between the HD & ram...and ram & HD...and nothing else.

I will add...that although it has been mentioned that if the page-out value is 10-20% of page-in value that more ram is suggested/needed...I'm pretty darn sure that I have personally had page-out values that EXCEEDED the page-in value.

When my MacBook Pro only had 2gig of ram...and if I would use it for weeks in a row without rebooting...my page-outs would be MUCH larger than 10-20% of page-ins.

So not a good situation.

- Nick

p.s. For example...here's a photo of someone's Activity Monitor I found on the internet (page outs almost equal page ins)...also notice only 1.5gig of installed ram:

04-18-2012, 03:48 PM

The size of the swap file can also be a measure of how efficiently a person 's Macintosh is running as well:

- enough ram/not enough ram
- HD is getting too full/full

This is why a Macintosh computer will "lock-up"...if the HD is full (or too full)...not enough room for the "swap-file":

Mac Virtual Memory – What it is, the Swap Location, and How to Disable Swap in Mac OS X

- Nick