I think the reseller is taking the drive that is advertised to be in the machine and replacing it with another drive, a cheaper version.  There are indications this is done for profit on the original drive sold separately.  When I got the computer it booted on a 38 gig internal flash drive.  Not sure if that is a faster boot or what, but the 1 T drive installed was neither formatted or mounted.  No response from the reseller when I discovered this and needed help getting the proper drive to boot.  Apple on the other hand was great and walked me through the process.  My two star rating is not for the product, but the reseller.