I have an Icy Dock 3.5" external enclosure with USB 2.0 and eSATA. I have an Intel DG45ID motherboard with USB 2.0 and eSATA ports. In the past I had a 2 TB Seagate drive in the enclosure, and it worked fine via either interface. I just bought a 3 TB Hitachi drive, and it shows up as 746.39 GB!
At first I thought, no problem, the USB storage controller in this couple-year-old enclosure just doesn't support drives over 2.2 TB (a famous limit, apparently). So I switched to eSATA, thinking that this would be a simple pass-through connection and it would work, because the enclosure isn't really doing anything with the interface then. But apparently it isn't so.
I have Windows Vista 64-bit, with the current patches. I initialized the disk as GPT, rather than MBR, as recommended in the GUI for disks larger than 2 TB.
So, what gives? Was I wrong that the eSATA enclosure just passes the SATA connection through unmodified? Is my motherboard to blame? Some drivers?
Edit: I just installed the Intel Rapid Storage software, which updated my SATA controller driver from 8.6 (dated 2-3 years ago) to 9.6 (dated a bit over a year ago). This didn't change how Windows Vista sees the drive, but it did install an "Intel Rapid Storage Technology" application which shows the drive as 3 TB! So, some part of the system sees the full drive size, but not the OS. What gives?