Memory Type: DDR2 PC2-5300, DDR2 (non-ECC)
Maximum Memory: 4GB
Please check the memory frequency of your iMac. Your memory upgrade needs to match the frequency of the installed memory. Note that the memory speed and the bus speed can be different.The SSD is fully functional in the system. The CTSSDCONVT ( 3.5" bracket ) is need to mount the SSD.
Memory or DRAM is the "working" memory of the computer. It's used to store data for programs (sequences of instructions) on a temporary basis.
Install Guide for your:
iMac 2.4GHz Intel Core 2 Duo (20-inch - 667MHz)
video - installing memory