5.10 Using the Promise Chip for RAID 0 or 1

The Promise® chip, PDC20276, onboard the P4T533, offers a high performance Redundant Array of Independent Disks (RAID) configuration that supports only UltraDMA-133/100/66/33, EIDE or FastATA-2 hard disks. After connecting two hard disks to the motherboard, activating either RAID 0 or 1 function is easily configured through the MBFastTrak133™ “Lite” firmware BIOS during boot up. In addition, the support CD permits installation of system drivers according to the Operating System (OS) on your computer. Read through this section in its entirety before setting up a new RAID system.

RAID 0 is also known as “data striping.” Striping optimizes two identical hard disk drives to read and write data in parallel, interleaved stacks. Two hard disks perform the same work as a single drive, and at a sustained data transfer rate double that of a single disk alone. The main advantage of a RAID 0 array is to improve the Speed Performance of data access and storage. With FAT32 and NTFS partitioning, the array will be addressed as one large volume.

RAID 1 is also known as “data mirroring.” Mirroring optimizes two identical hard disk drives to copy all data from one hard disk drive to the other and vice versa. As new data is written, it is duplicated onto both disks using a parallel write process. The main advantage of RAID 1 is that it greatly increases Fault Tolerance of the entire system, especially if each hard disk is connected separately to both ATA-133 IDE channels available on the P4T533. Should one hard disk suffer mechanical trouble, all system data will be preserved on the other drive.

IMPORTANT! Before setting up your new RAID array, verify the status of your hard disks. It is possible to use a pre-existing hard disk for RAID 0 only if the data is backed up before configuring the array as all hard disk data will be lost during the set up. RAID 0 requires at least two hard disks for optimal results. It is possible to use a pre-existing hard disk for RAID 1 to duplicate the source data; also, RAID 1 can set up two or more new disks. The Promise® chip, the FastTrak™ “Lite” BIOS and the FastBuild™ Utility on the P4T533 permit only two disks to be configured in RAID 0 or RAID 1 pairs and combinations; a third, “hot” spare hard disk may be used to support a RAID 1 array; (see the end of this section for more detail). For optimal performance, install only identical hard disks of the same model and storage capacity. Use only UltraDMA-133/100/ 66 compatible IDE cables and connectors. The Promise® chip also supports UltraDMA-133 specifications of up to 133 MB/sec per disk.

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Chapter 5: Software reference