SATA III drive in Mac OSX Lion

I wondered if I could switch the SATA port from the blue (SATA 3.0Gb/s) to white(SATA 6.0Gb/s) port since my hackintosh has been upgraded to LION so today I did just that and bang I’m on SATA III without any issue. But the weird part is I don’t feel any speed difference. With SATA III

1	time dd if=/dev/zero bs=1024k of=tstfile count=1024

2	1024+0 records in

3	1024+0 records out

4	1073741824 bytes transferred in 8.016426 secs (133942713 bytes/sec)

5

6	real    0m8.030s

7	user    0m0.004s

8	sys 0m1.381s

Divide 1024MB by 8 seconds and I got a write speed to 128MB/s on SATA III.

To satisfy my own curiosity, I plugged the hd (a 2TB Hitachi SATA III) back to the SATA II port and ran another write test. And the result turned out to be

1	time dd if=/dev/zero bs=1024k of=tstfile1 count=1024

2	1024+0 records in

3	1024+0 records out

4	1073741824 bytes transferred in 8.283360 secs (129626362 bytes/sec)

5

6	real    0m8.290s

7	user    0m0.004s

8	sys 0m1.179s

Which yields a 123MB/s, it’s slower than SATA III but not by much.

Thanx to ricochen.wordpress.com