User Guide

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This motherboard supports Ultra ATA33, ATA66 and ATA100 IDE devices. Following table lists the transfer rate of IDE PIO and
DMA modes. The IDE bus is 16-bit, which means every transfer is two bytes.
Mode Clock Period Clock Count Cycle Time Data Transfer Rate
PIO mode 0 30ns 20 600ns (1/600ns) x 2byte = 3.3MB/s
PIO mode 1 30ns 13 383ns (1/383ns) x 2byte = 5.2MB/s
PIO mode 2 30ns 8 240ns (1/240ns) x 2byte = 8.3MB/s
PIO mode 3 30ns 6 180ns (1/180ns) x 2byte = 11.1MB/s
PIO mode 4 30ns 4 120ns (1/120ns) x 2byte = 16.6MB/s
DMA mode 0 30ns 16 480ns (1/480ns) x 2byte = 4.16MB/s
DMA mode 1 30ns 5 150ns (1/150ns) x 2byte = 13.3MB/s
DMA mode 2 30ns 4 120ns (1/120ns) x 2byte = 16.6MB/s
ATA 33 30ns 4 120ns (1/120ns) x 2byte x2 = 33MB/s
ATA 66 30ns 2 60ns (1/60ns) x 2byte x2 = 66MB/s
ATA 100 20ns 2 40ns (1/40ns) x 2byte x2 = 100MB/s
Tip: To achieve the best performance of an Ultra ATA 66/100
hard disk, a special 80-wires IDE cable for Ultra ATA 66/100 is
required.