I've just built and configured a new 2012 R2 server but a first test backup of local data to tape resulted in very slow throughput
3.2GB, duration 7:56 @ 15mb/s
I would have expected a significant difference.
The server is a HP DL380e, RAID6, HP StorageWorks Tape enclosure (1 x DLT1 and DLT-S4) is attached to 2 x HP SC11xe which I understand are LSI Adapter, Ultra320 SCSI 2000 series, (w/1020/1030)(StorPort) and have used 2008 drivers.
The Tape unit is a Quantum DLT-S4, I had to use 2008 drivers which I found on the Quantum website
I have another server running with controllers on 2003 running BE2010R3 and using same Tape unit with 2306mb/s and most of that is over the wire.
This server has been built with the intention of replacing our existing BE setup but we cannot consider until we get decent throughput.