Technical information

V1.0 Vig625M Motherboard Manual

Chapter 5: Technical Information

NOTE: This chapter is indented for experienced users only, and only to be used as a

reference. Changes to or modify any of the components/ connectors listed herein can

and will seriously damage your system, including the motherboard, CPU and/or any other

hardware.

You do not need to read this chapter to configure your motherboard. If you are not sure

about the details listed herein, please skip and disregard them.

Enhanced IDE

IDE has been used in computer systems for some time, and has been a cheap solution

to data storage. It has now been realised that traditional IDE has its limitations and thus

needed to be improved. This was where Enhanced IDE came from. The main

developments to the IDE interface are:

 Support hard drives of capacity greater than 528MB. This is achieved through BIOS

changes.

 Improved data transfer rates. Transfer rates of 1-3MB/sec were the best to be

expected from older IDE drives. With local bus technology this increased to about

6MB/sec. Now with multimedia applications, requiring vast amounts of information,

even faster transfers rates were needed. Now drives with Enhanced IDE controllers

can deliver up to 13MB/sec which is in the region of SCSI-2 performance.

 Dual-IDE channels have now been added which allows up to four IDE drives to be

supported by the system. Each channel supporting two IDE devices.

 Non disk IDE peripherals have been developed (IDE CD-ROMs, IDE tape streamers)

which can be simply attached to the one channel requiring no special hardware

(requiring the use of an ISA slot) or complicated drivers. This is a standard interface

meaning that any IDE CD-ROM or tape streamer can be attached.

Operating Systems and Hard Drives

Standard CHS is the translation that has been used for years. Its use limits IDE capacity

to maximum of 528MB regardless of the size of the drive used.

Logical Block mode overcomes the 528MB maximum size limitation imposed by the

Standard CHS mode. It should be used only when the drive supports LBA (Logical Block

Addressing), and the OS supports LBA, or uses the BIOS to access the disk.

Extended CHS mode also overcomes the 528MB maximum size limitation imposed by

Standard CHS mode. It can be used with drives which are larger than 528MB that do not

support LBA.

Auto Detected allows the BIOS to examine the drive and determine the optimal mode.

The first choice is to utilise Logical Block mode if it is supported by the drive. The second