New drive operating in wrong mode

[ssilverm]

My Vista-based PC contains two disk drives, one for Windows and programs, the other for my data. A couple of weeks ago I replaced the data drive with a new 1TB Samsung Spinpoint disk. I have just noticed that it is running in PIO mode 4 instead of UDMA mode 5, and the DMA box in Device Manager is grayed out.

I'm guessing that this is causing me to derive less than optimal performance from the drive. Is that correct, and if so, is there anything I can do about it?

Steve S.

 

[RebateMonger]

Windows will usually do this if it detects a lot of errors generated from the drive or the controller. Anything in the System Event Log?

I believe there's a way to modify the Registry to get it running back in UDMA. But if more errors are sensed, Windows will set it back to PIO again.

 

[ssilverm]

Originally posted by: RebateMonger
Windows will usually do this if it detects a lot of errors generated from the drive or the controller. Anything in the System Event Log?

No, nothing obvious in the log. I'd be horrified if there were as the drive is brand new.

Steve S.

 

[RebateMonger]

Originally posted by: ssilverm
No, nothing obvious in the log. I'd be horrified if there were as the drive is brand new.

It's not unheard of for hard drives (and other mechanical devices) to experience early failures due to manufacturing defects. The early failures are called "infant mortality".

 

[Idontcare]

Originally posted by: RebateMonger
I believe there's a way to modify the Registry to get it running back in UDMA. But if more errors are sensed, Windows will set it back to PIO again.

This is true. I have to periodically hack my registry to get the UDMA mode set properly again on my DVD drives after attempting to play the random scratched/smudged children's DVD from netflix.

In my case the source of the problem (crap DVD quality) is known, so resetting my DVD drives to UDMA from PIO is a safe thing to do as I am not ignoring the root-cause of the PIO mode getting set.

In the OP's case I would recommend not resorting to hacking your registry to get UDMA back. You really should hunt down the root-cause, which will be some manner of bad hardware (possibly just a bad SATA cable).