Hard drive running at 4megs/sec

[shabby]

All of a sudden my main sata 250gig seagate is running very slow, hdtach clocked it at 4megs/second while my ide drive is running perfectly fine.
What in the world could be causing this? It doesnt seem like its taking any longer to boot, but copying stuff to it takes a while. Nothing has changed since yesterday and i have plenty of space.
Any guesses?

 

[shabby]

Whodathunkit, switching from one sata plug on the mobo to the other fixed the problem. How it started i have no clue but that gave me a scare

 

[shabby]

Alright im back to square one, after another reboot the drive is slow again. Here's a pic of hdtach doing its stuff http://putfile.com/pic.php?pic=12/35518104059.jpg&s=x12
I've narrowed it down to a windows problem since when i boot off my ide drive and run hdtach on the seagate drive everything is fine. I figure maybe its the sata drivers, but in device manage i only see ide controllers and nothing about sata. How could i re-install the sata drivers, or is that even possible?

 

[shabby]

Turned out to be the power supply, the 12volt line was reading 11volts :Q
Swapped out the psu with another one and everything is running dandy for the last 2 weeks.