Common Options : Enabled, Disabled

Details

32-bit Disk Access is a misnomer because it doesn't really allow 32-bit access to the hard disk. What it actually does is set the IDE controller to combine two 16-bit reads from the hard disk into a single 32-bit double word transfer to the processor. This allows more efficient use of the PCI bus as fewer transactions are needed for the transfer of a particular amount of data.

However, according to a Microsoft article about Enhanced IDE operation under WinNT 4.0, 32-bit disk access can cause data corruption under WinNT in some cases. Therefore, Microsoft recommends that WinNT 4.0 users disable 32-bit Disk Access.

On the other hand, Lord Mike asked someone in the know and he was told that the data corruption issue was taken very seriously at Microsoft and that it had been corrected through Service Pack 2. Although he couldn't get an official statement from Microsoft, it's probably safe enough to enable 32-bit Disk Access if you are running WinNT, just as long as you upgrade to Service Pack 2.

If disabled, data transfers from the IDE controller to the processor will only occur in 16-bits chunks. This naturally degrades performance so you should enable this BIOS option if possible. Disable it only if you face the possibility of data corruption.

You can also find more information on the WinNT issue above in our Speed Demonz' guide on IDE Block Mode!