Upgrading RAM in older iMac

I have an older iMac (mid 2007)) Model A1224 with a 20 inch screen. It has a 2.4 GHz Intel Core 2 Duo and currently has 2 GB 667 MHz Ram. I just upgraded to Mountain Lion and now it is running PAINFULLY slow. I can hardly bear to use photoshop or iPhoto now. How much more RAM can I put in this thing and will that likely resolve my problem? A year ago I upgraded the HD to 1 T and it is less than half full, so I don't think it is a space problem. Actually, it was running quite well prior to the OS upgrade. How about Crucial; can I use their RAM or is it advisable to stick with original parts. (I don't have any warranty left on anything.) Thanks for any help anyone can give me! One more thing, my printer doesn't seem to be compatible now, either. It is an Epson 730.

Your iMac officially from Apple can be upgraded to 4gig of ram…but unofficially it can be upgraded to 6gig.

Ram from either OWC or Crucial is fine:

- Crucial
- OWC

As far as OS upgrades. Generally speaking…the newer the OS upgrade…the more demanding it is on the computer hardware. So an older computer (6 year old iMac) probably won't run the latest OS as well as a newer computer (2-3 years old).

- Nick

Thanks for the reply. Is it safe to go to 6 GB? Can you elaborate a little on what else I can do to increase performance? Maybe I should just reinstall Snow Leopard . . . . is that even possible?

smallonetwo said:

thanks . . . is it safe to go to 6 GB? Maybe I should reinstall Snow Leopard . . . . is that even possible?

Click to expand...

Sure it's safe to upgrade to 6gig. But FYI...the 6gig upgrade costs 2x of the 4gig upgrade.

As far as reinstalling Snow Leopard. Sure you can reinstall it…as long as you have the original gray disks you got with the computer (if you bought it new)…or have a retail Snow Leopard install disk.

As far as the reinstall. Sometimes it's more difficult to "downgrade" the OS. You may have to wipe the HD to do it. The OS installers "like" to install from an older OS version to a newer version (10.6 to 10.8)…rather than the other way around (10.8 to 10.6).

- Nick