iMac 2007/2008/2009 20" RAM Upgrade Guide (iMac7,1 / iMac8,1 / iMac9,1) Rod Bland September 18, 2019 02:34 Updated Follow Use this guide to upgrade the RAM in your 2007/2008/2009 20" iMac to a maximum of 6GB (4GB + 2GB) Tools Phillips #1 Screwdriver Spudger Anti-static wrist strap Medium Anti-static mat Parts 1GB RAM Module 2GB RAM Module 4GB RAM Module Related articles iMac 2009 20" RAM Upgrade Guide (iMac9,1)