So I have a base (2.3/8GB/256) rMBP that has had some pretty bad lag and when I commit things sometimes they won't take (itunes track names etc.). So I ran the diagnostics and got: ALERT! 4HDD/11/40000000 SATA (0,0) My Macbook is only a few weeks old (Christmas Returns to Best Buy can be done until the 24th) so I am exchanging for a new one tonight. I'm worried about getting an IR screen (mine is perfect) but I don't want to take my brand new laptop to apple and have them replace the HDD. This is just documentation for others. I'll report how my new one is.