To check whether DMA mode or PIO mode is being currently applied to your drive:
Start/Run...type devmgmt.msc (this gets you into Device Manager).
Scroll down to IDE/ATA ATAPI Controllers. The controllers for hard drives and optical drives which are attached directly to the motherboard will be reflected. Each system normally supports at least 2 channels, a primary and a secondary. Each channel can support two devices and these devices are connected by the IDE cable.
If you right-click on any channel and select Properties/Advanced tab...you can see the two devices the channel reflecting your connection to the CD/DVD drive...and select Properties/Advanced Settings tab...you will see Device 0 (the device on the end connector of the cable) and Device 1 (the device on the "middle" connector).
You will also see the current transfer mode for each device. The current transfer mode for each device should reflect a given DMA level. On my systems, a hard drive is reflected as DMA 5 or DMA 6, while an optical drive (CD/DVD) is reflected as DMA-something (it varies).
If a drive of any sort is not connected and you have an empty connector, you will see "not applicable" in the Current Transfer Mode box.
PIO is an older transfer rate which used to be applied when drives were slower. On today's systems, one should not expect to see PIO mode reflected for any device attached.
But...at times, a system will revert to PIO mode for devices...for various reasons. This is treated as something that needs to be corrected, since the result is that devices do not function at their expected potentials.
There are solutions to this, regardless of why it happens.
I use the solution at Getting back to DMA mode in Windows XP - http://sniptools.com/tipstricks/getting-ba...e-in-windows-xp
. This solution involves editing the registry manually
, which I feel comfortable doing, at this point in my computer experiences.
But...there are other approaches (none of which I have tried): DMA reverts to PIO Windows Problem Solver - http://winhlp.com/node/10
Someone may know of simpler fixes, but these are the two which I've come across.
If you intend to do the edit of the registry, I urge you to take all necessary precautions before doing so and be aware that making registry edits that are incorrect...can have adverse impacts on your system's ability to function properly.