i guess it's the exact same module, only the first one is *tested* and *garantied* to work on a mac (for whatever that means) i suppose. if you go to newegg and check customers reviews on the value select chip, you'll find a mix of mostly satified and some unhappy customers. i was thinking of just buying the value select chip because the mac model is out of stock on the website i'm plannig to buy from but am afraid they won't help me if i get a problem and tell me i bought the wrong chip.