# time rsync -atrv /media/HD1/ /media/HD2/

sent 536590721350 bytes  received 9832345 bytes  60492706.58 bytes/sec
total size is 542353136411  speedup is 1.01

real    147m49.925s
user    71m43.300s
sys    58m15.608s

# time rsync -atrv –progress –stats /media/HD3 /media/HD4

Number of files: 2957
Number of files transferred: 2574
Total file size: 829508518604 bytes
Total transferred file size: 829508518604 bytes
Literal data: 829508518604 bytes
Matched data: 0 bytes
File list size: 83341
File list generation time: 0.001 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 829609967508
Total bytes received: 50450

sent 829609967508 bytes  received 50450 bytes  31480069.74 bytes/sec
total size is 829508518604  speedup is 1.00

real    439m12.535s
user    111m21.071s
sys    91m39.138s