SCSI-3
In 1993, work began on SCSI-3, from which Ultra-SCSI emerged. Since different interface technologies, various command sets and new functions had to be taken into account at this time, the SCSI-3 project was assigned to several working groups. During these activities, the actual name "SCSI" was renamed to SCSI Parallel Interface( SPI).
Because there are many versions under SCSI-3 and the SCSI Parallel Interface (SPI) that change and are updated, no SCSI-3 standard has been adopted yet. SCSI-3 stands for a data transfer rate of 20 MB/s for the 8-bit bus and 40 MB/s for the double-width bus of Wide-SCSI. The length of the SCSI cable is fixed at 3 m.
The transfer on SCSI-3 can be done as with SCSI-2 with single-ended and differential signals. SCSI-3 has 64-bit addressing and includes the definitions of the serial interfaces Fibre Channel( FC) and FireWire according to IEEE 1394 in the architecture model.