Well I want 8GB in this little baby. (VM is killing me). I find two types of 4GB DDR3 on Crucial (UK) one is 256x64 and other is 512x32) My question is which one is correct? (I have searched around and cannot find an answer). I know I could get from OWC but when postage and then the UK import duty and fee's are added its not a great difference so I may as well get it here.