This is the disk-disk backup running a full backup. I'm not sure if there's any software compression involved. If it was 2:1 then the throughput would be ~600MB/min I guess. The backup summary reports:
Backup Set Summary
Backed up 623608 files in 83315 directories.
Processed 197854446693 bytes in 2 hours, 25 minutes, and 54 seconds.
Throughput rate: 1293 MB/min
Compression Type: None
It's equivalent to 21MB/s that is SLOW for GbE connection