THE INTERFACE

One of the factors that affect the speed of a hard drive is the interface. Currently there are two common interfaces: EIDE and SCSI. The EIDE controller is integrated with the motherboard. The SCSI requires an extra controller since most motherboards don’t have integrated SCSI controllers.

Figure 29: Schematic diagram of the infrastructure of the typical computer.

The EIDE interface can connect a total of four devices to a computer bus such as 2 hard drives, a CD-ROM and a DVD.

The SCSI interface can connect up to 15 devices to a computer bus. There are several types of SCSI interfaces — 8-bit, 16-bit and even 32-bit. The transfer rate started at 5 Mbps for the old SCSI 1 evolving in increments up to the 16-bit, 40 Mbps Ultra2 SCSI, then the 16-bit, 80 Mbps Ultra2 Wide SCSI. The latest incarnation is the 32-bit, 160 Mbps Ultra3 SCSI or Ultra1 60. For normal computer operation, the performance of a drive receives only a small boost from the SCSI interface but for a website, you should seriously consider the SCSI.