I've got 2 hard drives in my PC, a 7 yr old WD 640Gb blue drive that I plan on replacing soon and a relatively new WD 1Tb Caviar Green drive. I use the green drive for data backup and noticed recently that when copying from the blue drive to the green or even from USB to the green it's painfully slow. I figured my blue drive was failing so I ran a sector scan and benchmark in HD Tune and everything came back looking really good. I ran the same test on the green drive and the sector scan came back all good but the benchmark is REALLY bad. Highest transfer rate 2.0Mb/sec. The drive is not even half full. Both drives are connected via SATA 3 cables/ports and I tried reseating them.
 
So does it sound like that green drive is toast or could something else be the culprit?

You should check under health what SMART info says.
 
AFAIK only the early 6 series intel chipset has a sata bug that could affect performance.
 
http://www.anandtech.com/...-chipset-begins-recall

I was referring to the controller on the drive itself rather than head/disk problems but still the drive, not sata port or mb issues..  The speeds still seem odd with the 0.00 minimum but the max speeds and burst speeds seem about right, tests consistently at a minimum of 0 and average under 30? I would no longer trust that drive.