Slow hard disk speeds

The hard disk is a Western Digital Caviar WD2000 (200GB, 186 formatted to NTFS) Serial-ATA drive. It has very slow read and write speeds; while hashing using DirectConnect++ the speed never goes above 9Mbits/s whereas hashing on a different physical drive results in speeds of over 40Mbits/s. Copying data from one drive to this is also very slow, although the media present on the disk can be played with no skipping. Only one primary partition exists on the drive.

I've used Western Digital's Data Lifeguard Diagnostics, which reported the drive as "pass".

If you have any ideas or suggestions, they would be appreciated.

Jam it back in, in the dark.

http://winhlp.com/WxDMA.htm

There's nowhere I can't reach.

haha grawl, i was going to link to that exact article.

that's happened at least 10 times to me in the last 4-5 months (on other peoples' computers). weird.

This thing is sticky, and I don't like it. I don't appreciate it.

Thank you for the prompt reply; I have read through the article. However, I cannot follow the registry fix because the drive is not IDE and I cannot identify the hard disk in question. Would it be safe to delete MasterIdDataChecksum or SlaveIdDataChecksum for all of the devices, as Windows will just generate them again? (Hopefully UDMA and not PIO.)

Update: I chose against deleting registry keys and instead, I've reinstalled the nVidia SATA drivers and for now the drive has been restored to full SATA I speeds; I presume this should remain so until the next 6 CRC errors. Thanks for your help.

Also, under IDE ATA/ATAPI controllers in Device Manager; I didn't have Primary IDE Channel and Secondary IDE Channel. Instead, I had nVidia nForce4 Parallel/Serial ATA controller. I had to open up one of these before accessing primary/secondary channel, and so I couldn't follow the solution entirely. (Such as Reactivating DMA, where I don't have Extended Settings.)

I am a dolphin, do you want me on your body?