pinwheeling under load

[jackotack]

Hi guys I have an iMac with a pinwheeling issue, wondering if anybody has any ideas how to minimize this issue.

One or two apps open is fine but more than that and I risk a situation where the computer pinwheels and stalls for 2-10 seconds. After that stall period is over then suddenly it 'catches up' i.e. it does the function I requested, or the web browser loads the page, etc.

It also happens if I switch windows to an app that I have not used for a while, or if I open or activate a feature in an app that I have not used since i opened it. I'm guessing this means the slowdown has something to do with retrieving that part of the program from wherever it is (whether it is is in memory or in virtual men or on the HD).

One thing that is common is the pinwheeling occurs when the Disk Activity graph is showing a spike, but the peak is only 5-10 mb/s. Is that a modest or a high rate of transfer?

I checked Activity Monitor. During pinwheeling CPU is fine, it can be <15% and still pinwheel. I check memory and usually I have at least 500mb free, (though if free memory drops to <10% then it goes unbearably slow).

The worst part is that once I hit the first pinwheel then nothing will speed things up again until I reboot. (ie close programs, free memory by typing PURGE at the terminal)

My boot time is 1:56 to the login screen. Then I type my username immediately and hit enter and then the total time to login and open Mail and view the first email message is 3:10 from pressing the power button. Is this normal for ML given my specs?

2008 imac 24"
2.8GHz Intel Core 2 Duo
2GB 800Mhz DDR2 SDRAM
320GB hard drive (140GB free)

Google Chrome
Mail
iTunes
(trying to) edit with iMovie
upgraded Leopard to Snow Leopard, then Mountain Lion + latest updates

At this point I am considering going back to Leopard (using my Snow Leopard time machine backup) but I would really like to stay with ML if I could just make it a little snappier.

appreciate any ideas, thanks

 

[simsaladimbamba]

2 GB is not much, especially foe Mac OS X 10.7 Lion or OS X 10.8 Mountain Lion.
You can upgrade that iMac to at least 6 GB using one 2 GB and one 4 GB module.

I have a 2007 Aluminium iMac with 4 GB and even with that much RAM, OS X 10.8 Mountain Lion was not really as fluid as Mac OS X 10.6 Snow Leopard, to which I reverted after being abused by OS X 10.8 Mountain Lion for a month.

Performance Tips For Mac OS X

 

[jackotack]

I went back to Snow Leopard, did a fresh install (meaning I only migrated Users, did not migrate Apps nor System files).

It worked fine for a week but today got into a serious slow down mode. It starts pinwheeling, and I open Activity Monitor to check it out and I have 1GB of memory free, CPU usage is less than 10%, Disk activity is minimal (less than 5 MB/second) and I have half my hard drive free (160 out of 320 gb).

Really bizarre is that when it starts getting slow I cannot even hear the hard drive whirring that you normally hear when a computer is 'busy.' That makes me think it is more than simply not enough resources.

Any other ideas are much appreciated.

 

[jackotack]

I never did resolve this. I toughed it out for a couple of months and then bought a new iMac. Wiped the old one and reinstalled Leopard, which ran fine.