If your running a Windows XP OS, I know a way how to find if your IDE HDD is running at the speed it's suppose to, I think it's similar for SATA too, never had a SATA so I can lead you to direct spot so you'll have to search a bit.
Control Panel > System > Hardware > Device Manager > IDE ATA/ATAPI Controllers > Properties > Primary Channel > Test Speed
So when you go to device manager search where it says SATA or Serial ATA, and it should be similar like for ATA's... I think