I am a cheapy person and wondering if my iMac Core Duo will accept RAM from GB micro? Also, will it accept 400 MhZ Ram?? Or do I have to get 667 MhZ like my stock 512 MB? Please help. I normally have iTunes, Safari, aMSN, and some other stuff and i Am needing more than the stock 512! I am afraid to open QuickTime with those three apps open. My ram will explode. OMG safari is a ram hog!