Answer to: Problems upgrading the systems memoryI just upgraded my early 2008 20" iMac to 6GB. I bought the upgrade package (2GB + 4GB) from Other World Computing (OWC). Seems to work fine. Just make sure each memory chip is in the correct memory slot. Otherwise, you will hear a continuous 3 beeps.
Answer to: iMac 2008 20inch - CPU upgradeOn my early 2008 20" iMac (in addition to 6MB RAM, and installing an SSD drive), I just upgraded the following: Core 2 Duo E8335 SLAQC (C0) 2.67 GHz 6 MB 1066 MT/s 10× 44 W Socket P April 2008 FF80576GH0776M to Core 2 Duo E8435 SLGEA (E0) 3.07 GHz 6 MB 1066 MT/s 11.5× 44 W Socket P March 2009 AW80576GH0836M Make sure to remove and add thermal paste. Seems to work fine. They are the same size, use the same wattage, and same bus speed.
Answer to: RAM Upgrade help for 8,1 iMacI just upgraded (3-9-16) my early 2008 20" iMac to 6GB RAM package from Other World Computing (OWC). You just have to make sure the 2GB and 4GB go in the correct slots. Otherwise, the computer will continue to beep 3 times. Seems to be working fine so far.