> WD Caviar black 2TB internal sata, less than a year old, less than half full, > recently defragged, tried multiple sata ports and restarts. If I copy something from > it to another drive it starts fast and then slows down to like 7 MB / sec. I used to > use it for video recording and now it's not able to do it anymore, just gives > constant frame skip. Loading stuff from is is slow as hell. I would think it's on its > way out but it's not even a year old. Faulty?
What OS? XP through 7 will kick a drive down to PIO mode after a number of errors or timeouts.
Check your system logs for timeout or crc errors on that drive. Could be a bad cable, could be the controller board. WD has a great diagnostic suit too. Could just be a bad sector that you can eliminate with the tools