Solving UDMA Mode Problems with ATA/IDE Drives
Originally, all ATA/IDE drives used an access method called PIO (programmable input/output). Today, ATA/IDE hard drives (and some types of ATAPI drives) support faster access modes known as UDMA (also called Ultra DMA or Ultra ATA), which range from 33MHz to 66MHZ, 100MHz, and the latest 133MHz speed. If you notice the following problems, your system probably doesn't have UDMA configured correctly:
Very slow hard disk and optical drive performance
Inability to use disk-mastering software with your CD-RW or writeable DVD drive
To achieve a particular UDMA speed, all of the following must be present:
The correct cable must be used. While UDMA/33 drives can use the older 40-wire IDE cable, UDMA/66 and faster drives must use the 80-wire UDMA cable.
The drive must be configured for the fastest UDMA speed supported by both the drive and the host adapter.
The host adapter (motherboard or slot-based) must have its Windows device drivers installed for maximum performance. View the ATA/IDE host adapters in Device Manager to determine if you need to install device drivers; if the host adapter listing in Device Manager indicate that the correct drivers are not installed, download them from the motherboard or system builder's Web site and install them. See "Using Device Manager," p. 480 for details.
The correct UDMA speed must be selected in the system BIOS setup for the drive if User-defined, rather than AUTO, is used to configure the drive.
Because drives with fast UDMA modes are frequently used on motherboards that support slower UDMA modes, most drives are shipped with their faster UDMA modes disabled. Use the utility disk supplied with the drive, or download a utility from the drive maker's Web site, to view and change the UDMA support for your drive.