Ok so you will all tell me to stop messing about with old tech, but I like to tinker around. So to anyone who might be interested or be able to offer advice please read on. I have a mid 2007 20" imac but have read a guide to install sierra. However my 2GHz is not supported need the 2.4GHz or 2.8GHz extreme. Can anyone tell me what socket the imac uses? I found a few CPUs online/ebay/etc. I would like to swap the cpu as they are cheap. I will be fitting more ram to max out at 6GB and a 120GB SSD too. I love this imac and with these mods should last me a few more years until I can afford a new imac. So any help is much appreciated.