DMA ( Direct Memory Access )is not a kind of HD.

Microsoft Windows includes a Bus Mastering feature known as Direct Memory Access or DMA. When this DMA feature is enabled, it basically allows your Hard Drive and CD Rom Drive to transfer their information directly to and from memory without passing through the Microprocessor. Hence the word, Direct Memory Access. In short, when your disk drives use Direct Memory Access to access their information, this reduces the load placed upon your CPU and your system works faster.

Essentially, Direct Memory Access (DMA) is the theoretical data access rate of a Drive measured in megabytes per second. For instance, an Ultra DMA-100 Hard Drive will theoretical access data at a rate of 100 megabytes per second and an Ultra DMA-133 Drive will theoretical access data at a rate of 133 megabytes per second. Therefore, this technical brief will show you how to enable Direct Memory Access (DMA) on your Computer System.