Hello goodmana1, Yes the MD3200i will support 3tb sata drives.  Here is a link to the hard drive matrix & if you look on page 7 & 8 it list out which 3TB drives are supported. support.dell.com/.../matrix.pdf Let us know if have any other questions.
Will an MD3200i take 3TB SATA drives? Or only 2TB SATA drives?
Maximum HD size in MD3200i?