hdparm ata raid as sda

[carpman]

Hello, i have got my hardware raid array on ITE raid with 2x40 gb diamond max 9 hd working. The shows as sda, i can do

hdparm /dev/sda

/dev/sda:
readonly = 0 (off)
geometry = 9996/255/63, sectors = 160586368, start = 0


can even do
hdparm -tT /dev/sda

/dev/sda:
Timing buffer-cache reads: 1200 MB in 2.00 seconds = 599.40 MB/sec
Timing buffered disk reads: 122 MB in 3.07 seconds = 39.79 MB/sec


but if i try and pass option i get error about it being scsi drive, does this mean that i can't improve performace?

cheers
_________________
Work Station - 64bit
Gigabyte GA X48-DQ6 Core2duo E8400
8GB GSkill DDR2-1066
SATA Areca 1210 Raid
BFG OC2 8800 GTS 640mb
--------------------------------
Notebook
Samsung Q45 7100 4gb