I was looking at system profiler to find what hard drive I had installed in my MBP (awhile ago forgot the name of it). I basically took out the stock 320GB because it was too loud and put in my 2009 MBP's 160GB hard drive in it. I saw that the Link Speed is 3GB but the negotiated is 1.5GB, does that mean my system is running slower? could explain the beach balls... Also I would like to buy the same model/type as the HD but bigger memory, I am running right now but am not sure how to read which model it is. System Profiler says its: Hitachi HTS545016B9SA02. Thanks!