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Do I need more RAM? (imac 21,5, activity monitor capture)

Romf

Romf

macrumors 6502
Original poster
Jun 11, 2011
265
87
Paris, France
Hello everyone,

Well my iMac has been quite slow for a few days. In fact since I've been installing an airport extreme with a usb disk and making my timemachine transfer on this disk, using it quite much besides.
for the past day time machine has been backing up through ethernet. But I don't really know if the slow downs are due to RAM, CPU or HDD.
I've set the activity monitor dock icon to show the CPU usage and it nearly never goes to 100% even during a slow down.
That would leave us with RAM or HDD. I've attached a screenshot of the activity monitor which shows very little free RAM, although I've read this could be quite normal due to the Inactive RAM.

My iMac software are up to date, here's what's runnig:

Time machine backing up to ethernet
firefox (5 tabs)
thunderbird
adium
skype
rss client
spotify
activity monitor

Thanks!
 

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Oh, and I forgot. At the time of the capture there was no slow down, but just before the free ram went down to 20mb :) (4GB in the mac)
 
Upgrade to 8GB of RAM and you'll be good.

Some might say that it's more than what you need but it's not going to cost you a kidney and if you ever open up something like iMovie or whatever to do something creative, you'll be glad.
 
Vylen said:
Upgrade to 8GB of RAM and you'll be good.

Some might say that it's more than what you need but it's not going to cost you a kidney and if you ever open up something like iMovie or whatever to do something creative, you'll be glad.
Click to expand...

Thanks for your answer.

As the upgrade will make all the imac memory ports used, is there any point in upgrading to 12GB (adding 2x4GB) at all?
 
Romf said:
Thanks for your answer.

As the upgrade will make all the imac memory ports used, is there any point in upgrading to 12GB (adding 2x4GB) at all?
Click to expand...

Please do that. 2x4GB is not much more expensive than 2x2GB. Makes more sense to go for 12GB. Thats what I did with my previous iMac.
 
EEXOOO said:
Please do that. 2x4GB is not much more expensive than 2x2GB. Makes more sense to go for 12GB. Thats what I did with my previous iMac.
Click to expand...

I just did this and have 12gig in my iMac 21.5" 3.06 i3.

It hasn't changed my life but iPhoto loads quicker by a split second.

the price of ram these days it wasn't that much of an issue to do it or not.
 
Romf said:
Hello everyone,

Well my iMac has been quite slow for a few days. In fact since I've been installing an airport extreme with a usb disk and making my timemachine transfer on this disk, using it quite much besides.
for the past day time machine has been backing up through ethernet. But I don't really know if the slow downs are due to RAM, CPU or HDD.
I've set the activity monitor dock icon to show the CPU usage and it nearly never goes to 100% even during a slow down.
That would leave us with RAM or HDD. I've attached a screenshot of the activity monitor which shows very little free RAM, although I've read this could be quite normal due to the Inactive RAM.

My iMac software are up to date, here's what's runnig:

Time machine backing up to ethernet
firefox (5 tabs)
thunderbird
adium
skype
rss client
spotify
activity monitor

Thanks!
Click to expand...

your page ins are 1.7 gb your page outs are .8 gb I have 10gb ram my page ins are 1.12gb page outs are 0 gb
 

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Definitely just do the 12gb upgrade. I ordered off Newegg 2x4gb chips a few days ago and got my order for like $73 shipped. For me, it was a no-brainer. You already have a powerhorse of a machine like the iMac, what's 80 bucks for enough RAM to never worry about it, really no matter what any consumer/prosumer will ever do.
 
Here are some things to understand about the activity monitor when thinking about getting more RAM:

* The free and inactive (green and blue) combined is available to apps. So at the moment of the capture you have plenty of RAM free. (OS X caches the files it reads from disk and that shows up as inactive RAM. But the cache is low priority and will give up its RAM to any process that wants it.)

* Page outs is the the number you really want to look at. When that goes up, it means that something ran out of free RAM and so the contents of active RAM was swapped to disk. That's really slow. And when the swapped RAM is accessed, it is really slow to retieve it from disk.

* However, you can't just look at the page outs number. You might have been running you computer for ages and only very rarely did page outs occur.

* Also, one common reason for page outs is one bad app (or often a bad Safari plug-in -- you guess which one is the worst) has a bad memory leak. More RAM doesn't fix a buggy app.

What you want to look for is page outs increasing over time as you do your normal-heavy activities. If that happens, get more RAM. If not, it probably isn't going to help you much.
 
So its slow while you are doing the TM backup?

That is to be expected!

before tossing $80 out, wait for the TM backup to finish, restart, then see if its slow again.

I bet its not.

While doing an intensive background process like TM the rest of the Mac is going to be slow. Just wait for it to finish.
 
iSee said:
Here are some things to understand about the activity monitor when thinking about getting more RAM:

* The free and inactive (green and blue) combined is available to apps. So at the moment of the capture you have plenty of RAM free. (OS X caches the files it reads from disk and that shows up as inactive RAM. But the cache is low priority and will give up its RAM to any process that wants it.)

* Page outs is the the number you really want to look at. When that goes up, it means that something ran out of free RAM and so the contents of active RAM was swapped to disk. That's really slow. And when the swapped RAM is accessed, it is really slow to retieve it from disk.

* However, you can't just look at the page outs number. You might have been running you computer for ages and only very rarely did page outs occur.

* Also, one common reason for page outs is one bad app (or often a bad Safari plug-in -- you guess which one is the worst) has a bad memory leak. More RAM doesn't fix a buggy app.

What you want to look for is page outs increasing over time as you do your normal-heavy activities. If that happens, get more RAM. If not, it probably isn't going to help you much.
Click to expand...

this

I have my MBP running now for 15 days and my page outs are at 584.9 MB which practically means I never ran out of Ram. However if you have something like 800 MB of page outs after say 1-2 hours, then you definitely need more ram for the system to run smoothly. Also going to 8+ Gb of Ram makes any system nowdays run a tad smoother. I would also recommend going for as much as you can put in, as Ram is really cheap these days.
 
From that activity monitor screenshot, I'd say you don't really need any more RAM. As others have said, it's the Page outs (and Swap used) that are the real indicators of RAM constraints.

It won't do any harm to increase your RAM and is pretty cheap, but don't expect dramatic speed increases as you're not really straining what you've got now

for comparison, I've got 8GB in my iMac and my Page Outs (in the last 2 days) are 5.88GB and my Swap used is 3.42 GB. I run a lot of virtual machines, and 8GB clearly isn't enough based on those figures (which is why I've got 16GB on order :D)
 
Badger^2 said:
So its slow while you are doing the TM backup?

That is to be expected!

before tossing $80 out, wait for the TM backup to finish, restart, then see if its slow again.

I bet its not.

While doing an intensive background process like TM the rest of the Mac is going to be slow. Just wait for it to finish.
Click to expand...

Well yes but then every hour I'll have a TM backup running....
This was the case before when I did it on a firewire disk, but here as I have to start the backup from zero (620GB to backup through ethernet), it is just a longer backup than before... And well the iMac has been pretty slow since this (it's been rolling for like 1 day now).

Well anyway, I think I'll wait for the big 1st backup to finish, then see if I get some more slow downs.

Thanks everyone, I'll keep you posted!
 
I've ordered more RAM for my new 21.5 iMac, I've been getting lots of slowdown.
Pretty disappointed to be honest, I expected I would be able to do a lot more with that when compared with my 2007 MacBook.
Something to lookout for, Firefox has memory problems in my experience, try switching to Safari and seeing how that is. It has alleviated some of the problems but to be honest I still think the extra RAM is worth it what with Lion on the way with its philosophy of not closing down applications.
I got 8GB extra by the way
 
To learn if an iMac needs more RAM, surf:

http://osxdaily.com/2010/10/29/does-your-mac-need-more-memory-how-to-know-if-you-need-a-ram-upgrade/

As stated in above URL, "if Page outs are 10% or more of Page ins with regular computer use, I recommend a memory upgrade. ".

In a different source, I read the at "average loaded" iMac with 500+ MB or Free RAM (bright green slice) is a very healthy iMac.

For me, I like using the 500+ MB "Free" rule. Since the OP's iMac only has 179.2 MBs of Free memory, I would add more RAM. As many stated, RAM is "low cost" these days. It isn't worth nickle and diming over.

Seriously..... If you plan to keep your iMac for many years, simply buy 4 GBs of more ram. re: Buy 2x2 GBs and install them. And for a few more dollars, buy 2x4 GBs and have have a total of 12 GBs (even though 8 GBs would work great).

Good luck...
 
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Badger^2 said:
So its slow while you are doing the TM backup?

That is to be expected!

before tossing $80 out, wait for the TM backup to finish, restart, then see if its slow again.

I bet its not.

While doing an intensive background process like TM the rest of the Mac is going to be slow. Just wait for it to finish.
Click to expand...

My computer never slows down during a backup.
 
Romf said:
I'm sorry but I don't really understand what all that means :D Can you explain? :eek:
Click to expand...

you have 50% page outs terrible buy ram. you computer pages out when it needs ram so your computer is looking for more ram on every other op.
I have 0% page outs with 10gb


you have 50% pageouts with 4gb ram add some ram.
 
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Romf, Time Machine is not supported on USB disks attached to Airport Extreme. It seems to work most of the time, but not all the time.
 
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