Share the raid partition through CIFS/SAMBA and test the performance using http://www.808.dk/?nastester
hdparm -Tt /dev/md0
returns:
/dev/md0: Timing cached reads: 4284 MB in 2.00 seconds = 2142.08 MB/sec Timing buffered disk reads: 586 MB in 3.00 seconds = 195.15 MB/sec