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Yellowstone2012

macrumors regular
Original poster
Feb 3, 2011
108
0
I have had this iMac since March 2009 (making it a late 2008 model), and recently, I have been starting to get the spinning wheel when working in Xcode. After I quit Xcode when I get the chance, Firefox starts sizing up. Its pretty much a random case of waiting or force quitting (if I can) the application.

This is my model: http://www.everymac.com/systems/app...20-inch-aluminum-early-2008-penryn-specs.html


Any ideas of what could be causing this?
 

johnfkitchen

macrumors regular
Sep 7, 2010
210
0
The first suspects I'd look for are a RAM shortage or possibly a hard disk problem.

Run Activity Monitor and check the amount of Page Outs vs the Page Ins. If Page Outs is greater than 10% of Page Ins, then either run fewer concurrent programs or upgrade the RAM.

But also run Disk Utility, repair Permissions and Verify your disk.

Report back and we can figure out the next steps.
 

Detrius

macrumors 68000
Sep 10, 2008
1,623
19
Apex, NC
This percentage people are saying about pageouts vs. pageins is BS. If pageouts is greater than zero, then by definition, you don't have enough RAM for what you're doing. There is no arguing with this. You've run out of memory. People are trying to argue this percentage as a measure of how bad it really is, but even that is logically flawed. Suppose you've been using the machine for a week, and then suddenly, you want to use 4GB more RAM than the 2GB total you have. Well, the percentage will be low, but clearly, you need more RAM in your machine.

Also, repairing permissions for slowness issues... superstition.
 

GGJstudios

macrumors Westmere
May 16, 2008
44,545
943
This percentage people are saying about pageouts vs. pageins is BS. If pageouts is greater than zero, then by definition, you don't have enough RAM for what you're doing.
I agree. Page outs are an indication of insufficient RAM, regardless of the ratio to page ins.

OP, also be aware that page outs are cumulative since your last restart. To get an accurate picture, restart to set the page outs to zero, then track them under normal use to see if you're paging out with a normal workload.
Also, repairing permissions for slowness issues... superstition.
Also true. Many people don't even know which permissions are repaired and which ones aren't. It's not a "cure-all".
 

Badger^2

macrumors 68000
Oct 29, 2009
1,962
2
Sacramento
Since this a recent thing -- then I highly doubt its an issue with RAM -- or you would have noticed it the day you bought it.

And a bad drive is not an indication of random slowness in an application. Sounds like an application/software issue.

Have you tried creating a new user and giving Xcode a shot? What happens to those apps then?

What about your other apps? mail? iPhoto, iTunes, etc? Do they slow down too?
 

johnfkitchen

macrumors regular
Sep 7, 2010
210
0
This percentage people are saying about pageouts vs. pageins is BS. If pageouts is greater than zero, then by definition, you don't have enough RAM for what you're doing. There is no arguing with this. You've run out of memory. People are trying to argue this percentage as a measure of how bad it really is, but even that is logically flawed. Suppose you've been using the machine for a week, and then suddenly, you want to use 4GB more RAM than the 2GB total you have. Well, the percentage will be low, but clearly, you need more RAM in your machine.

Also, repairing permissions for slowness issues... superstition.

Detritus, do you have a quantified method of determining how much Page Out activity is too much? One page out per day is not a problem, 100 per second probably is, but what's a good rule of thumb?
 

GGJstudios

macrumors Westmere
May 16, 2008
44,545
943
Detritus, do you have a quantified method of determining how much Page Out activity is too much? One page out per day is not a problem, 100 per second probably is, but what's a good rule of thumb?
It depends on what's running. For example, you may run all the apps you normally do for weeks with no page out activity. Then you may have a rare need to do something that causes paging, either a little or a lot. Then you may run for weeks with no paging activity. In such a case, you probably don't need more RAM, as your needs that exceed your RAM are infrequent.

On the other hand, if you're consistently paging out with your normal workload, especially page outs in GBs rather than MBs, you could probably benefit from more RAM.

Again, remember that page outs are cumulative, so if you run for 2 months with no paging except 3 different days where you page out, your page outs shown in Activity Monitor will be the accumulation of those 3 days.
 

Detrius

macrumors 68000
Sep 10, 2008
1,623
19
Apex, NC
Yes, the "page out" number is cumulative, but "swap used" is not. It's a measure of how much has been paged to disk and is still there right now. Again, anything greater than zero means you don't have enough RAM. Whether you should rush out and buy more is a different story, and there is no clear answer to that question because it ultimately comes down to one question: can you afford more. If the answer is yes, then it doesn't really matter what the numbers look like. Just get more RAM and be done with it. If "swap used" is 3GB, you need at least that much more RAM.

You can watch the system paging to disk at the command line using "vm_stat". For example, "vm_stat 15" spits out a line every fifteen seconds showing memory usage. These numbers are in pages, and one page is 4kB.

Really, if you're seeing beachballs and there are signs you don't have enough RAM, then you really should be getting more RAM. If you have a lot of programs open but almost never switch between them, then paging out and paging in is a little like saving your documents, closing the program, and then reopening, but it happens in the background.

There's the question of whether you don't have enough RAM, and that's very simple to answer. If pageouts is greater than zero, you don't have enough RAM. The other question of whether you should buy more is not so simple. If pageouts is greater than zero, and you can easily afford more, then buy more. Your system will put it to good use. You can never have too much RAM. If you can't easily afford more RAM, well... you'll just have to figure out if it's worth it to yourself.
 
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