This technology for transferring data between a computer's hard disk and memory was developed by Quantum and Intel. The maximum burst rate of an Ultra DMA hard drive is 33.3 MBps. The original DMA (Direct Memory Access) protocol could only transfer data at half that speed.
Thanks to Ultra DMA, programs can open faster and run more smoothly. This is because Ultra DMA can send more data to the memory in less time than the original DMA. Ultra DMA also has a built-in utility called Cyclical Redundancy Checking (CRC) that helps protect data integrity. So if you want a nice, fast hard drive, look for one that supports Ultra DMA.