HDD Data Transfer Protocols
PIO is a method of transferring data between the running software and a peripheral using special CPU instructions. The PIO protocol requires lots of CPU overhead to transfer the data. As a result of this inefficiency, a system's performance can be significantly decreased.
DMA is a hardware-based feature that allows individual devices to access system memory for reading and\or writing independently of the central processing unit (Multiword DMA and Ultra DMA protocols). This feature also allows CPU to perform other work during the reading and\or writing. 80-pin interface cable is required for Ultra DMA-3 mode and higher.
The throughput of data transfer protocols (MB/s)