Computer just old, or out of RAM?

[yortzec]

I have a late 2006 Intel iMac with 1 GB RAM. In the past 6 months or so, it's been getting slower and slower. Especially noticeable is that it takes upwards of a minute to open any application after waking from sleep.

I've been keeping Activity Monitor open, and even at times where the computer is thinking and temporarily freezing, it says that I have plenty of RAM idle (usually about 50% or more).

So, would more RAM help this computer? If not, why might it be running so slowly?

Thanks for all the help!

Sincerely,
yortzec

Additional Specs:
2.16 GHz Intel Core 2 Duo
Mac OS 10.5.8
RAM is 2 x 512MB, both came with the computer. Both say they have a bus speed of 667 MHz.

 

[spirit]

Upgrade to more RAM if possible, get the max your Mac can hold, and then maybe reinstall Mac OS if you can. 6 years is a pretty long time to go without reinstalling. Reinstalling should make it faster once you've upgraded the RAM.