Another DMA -> PIO Hard Drive Question

[Peter]

Is there something I can change in the registry to fix the following
problem described in MS Knowledge Base #817472. The problem is affecting
the performance of the hard drive in my PC. Quoting the KB article:

"After the Windows IDE/ATAPI Port driver (Atapi.sys) receives a cumulative
total of six time-out or cyclical redundancy check (CRC) errors, the
driver reduces the communications speed (the transfer mode) from the
highest Direct Memory Access (DMA) mode to lower DMA modes in steps. If
the driver continues to receive time-out or CRC errors, the driver
eventually reduces the transfer mode to the slowest mode (PIO mode)."

My hard drive has been reduced from DMA to PIO. When ATAPI knocks the
mode down from DMA to PIO I assume it stores that fact in the registry.
Where? Is it possible to edit the registry to set the mode back to DMA?

(Note: The problems on my hard drive which caused the knock down from DMA
to PIO mode have since been fixed.)

Peter

 

[Joseph Conway [MSFT]]

Further down in that same article is the solution I think youre looking for:

WORKAROUND
==========

To re-enable the typical, or faster, transfer mode for an affected device:

1. Double-click "Administrative Tools", and then click "Computer
Management".

2. Click "System Tools", and then click "Device Manager".

3. Expand the "IDE ATA/ATAPI Controllers" node.

4. Double-click the controller for which you want to restore the
typical DMA transfer mode.

5. Click the "Driver" tab.

6. Click "Uninstall".

7. When the process completes, restart your computer. When Windows
restarts, the hard disk controller is re-enumerated and the transfer
mode is reset to the default value for each device that is connected to
the controller.

Also, that is a hotfix article, you can call tech support and they will send
you the fixed file for free.

 

[Peter]

Joseph,

I did see that workaround you mentioned in the KB article but I was
concerned about doing it. If I uninstall the driver for my only hard
drive will I be able to restart/reboot my PC?

I can see doing that workaround if the problem were with a non boot drive
such as a CD but wont uninstalling the driver for my hard drive prevent
the hard drive from working/booting??

Peter

 

[Joseph Conway [MSFT]]

You "should" be fine, the drive will auto reboot the machine and redetect at
boot.