Ask Max: Does adding iMac RAM alter the normal operating temperature?
Two quick questions: Is it normal for an iMac to run a bit hot? Mine seems to settle around 120 degrees. Is that normal? Secondly, I want to add memory to my iMac (24 inch with 2GB of RAM). Can you suggest the best way for me to go?
Here is a handy little list of user recorded Mac system temperatures assembled to help others determine what is normal temperature for their Mac.
From the list, it looks like your iMac is in the proper range. As for RAM upgrades, you can go up to 3 GBs if you have a white plastic iMac or 4 GB if you have an Aluminum iMac released before 2009. Depending on what iMac you have, you can buy one or two of these 2GB stick. You only have 2 RAM slots so you will have to remove one stick of 1GB RAM for each 2GB stick of RAM you add.