If you have an Overland library installed with LTO4 FC tape drives be aware that the Windows Firewall, even though deactivated, will limit the performance to the drives as long as the service is running.
Tests showed a ca. 40MB/sec performance to drives when the service was running. Connecting the drives to a Windows 2003 machine gave full performance. Once the Windows Firewall was completely deactivated the performance to the tape drives increased dramatically and the expected performance was obtained.
This might also happen on LTO3 and LTO5 fibre channel tape drives but this has not been verified at this time.