Sluggish performance on older iMac

See:

Mac Maintenance Quick Assist,
Mac OS X speed FAQ,
Speeding up Macs,
Macintosh OS X Routine Maintenance,
Essential Mac Maintenance: Get set up,
Essential Mac Maintenance: Rev up your routines,
Maintaining OS X,
Five Mac maintenance myths, and
Myths of required versus not required maintenance for Mac OS X for information.

One observation is that a number of people have reported poor performance running Lion in 2GB of memory. You can install two 2GB cards for 4GB, although the system may only use between 3GB and 4GB. The system will run a bit faster with matched RAM cards (2 x 2GB) vs unmatched cards (1GB + 2 GB). Those that had unsatisfactory performance with Lion at 2GB have indicated they were pleased with the performance after upgrades to 4GB.

Dear BGreg,

I experience a similar problem on my late 2006 iMac. However, I can't remember that my mac got sluggish right after the Lion upgrade. Right now, it's gotten so sluggish that I'm considering a new machine, even though I think it's still fine for my requirements.

After reading your post I checked my system information and to my surprise I saw the following:

So it says 3 GB ???

Also see this screenshot:

It seem like my memory cards aren't recognised anymore. In that case I know what to do, either re-seat them or replace them.

However, when I check the old system profiler window it says the modules are 'OK'.

This must be the explanation for an iMac that has gotten so sluggish it's nearly impossible to work with.

What do you (or anybody else with similar issues) think?

Thank you so much for all your input!

Eaglepeak

Couple of things .... if it were me, I would install a second 2GB memory card in place of the 1GB card, because the Intel architecture runs a little quicker with matched RAM cards, about 3% to 5%, as I recall from others who have tested that. The system will still see 3GB, you just pick up a slight performance improvement.

I notice your Lion is at build 11D50. Mine is at 11D50b. You might want to download the combo update from http://support.apple.com/kb/DL1484 and apply it. Go into Disk Utility and repair permissions first, apply the combo update, then repair permissions again. Then see if you still get the same 3GB ???

Baltwo listed some good resources on optimizing OS X. One more is http://www.thexlab.com/faqs/performance.html

I'm sure already included is one or more of the links baltwo listed included running OnyX, which can make a performance difference. Download it from http://www.titanium.free.fr/download.php . Run the tasks on the cleaning and maintenance tabs.

And of course, make sure you have free disk space for the system to work in.

Thanks a lot BGreg.

I just re-seated the memory modules, and the iMac is amazingly back to normal performance again. Check my tweets if you like @gmpatmaca. This is a big relief because I don't need a new one yet.

I'm also considering buying two new 2 GB memory modules since they're really cheap anyway.

I'll check out the combo SW update.

Thanks a lot once again for getting me on the right track!

I'm still not satisfied with the overall performance despite the ram modules being recognised correctly. Do you think it still makes sense to update to build 11D50b?

Thanks again!

PS: I'm waiting for two 2 GB modules to arrive by mail order, so I will try that in a couple of days as well.

When you're trying to solution performance issues, it may make sense to be at the latest level of the operating system, which in this case is "b" (we hope it solves more than it hurts 😁). It should not hurt anything to install it. If you want, wait until you install the new memory, then go from there.

Have you considered running xbench, available from http://xbench.com ? It's a benchmarking program, then you can compare your system results to others in their database? That might help identify any areas to look at, too.