I'm waiting on my new Dualcore 2.3 PM now, its coming with 1 gig of non ECC RAM in it. I'm going to buy another gig of RAM from Crucial, and i noticed that they only charge £10 more for the ECC versoin of their 1 gig kits. Since the Apple RAM in my Mac will be Non ECC, i was wondering, can i / should i mix them, or keep them the same? If it is possible to mix them, is there a way to get it so that the Crucial ECC RAM is the 'primary' RAM, so that it is the 1st pair of RAM chips to use if i need less than 1 gig of RAM? Or will OSX spread the RAM accross all the chips regarless of total useage? Any help would be great!