Highpoint HPT370 ATA/100 RAID Controller Chip
Last updated: 7/27/00

This 144-pin chip is starting to show-up on motherboards and ATA/100 controller expansion boards.  What it does is what the motherboard chipsets don't do yet.  It brings ATA/100 performance and a couple of extra IDE interfaces to motherboards, and RAID features to IDE hard disk drives.  So, I thought this little gem deserved its own little article...

What is ATA/100?  Ultra ATA/100 is an updated version of the ATA/66 disk drive data bus introduced by Quantum in 1998.  The ATA/100 specification defines a physical layer operating at 100 megabytes per second (MBs).  It is backward compatible with ATA/33 and ATA/66 enabled devices; i.e., ATA/33 and ATA/66 drives can be connected to an ATA/100 interface.  ATA/100 drives use the same  80-conductor, 40-pin cable introduced for by ATA/66 standard.  If an older, 40-pin IDE cable is connected to an ATA/100 (or ATA/66) interface, it will work; however, the drive will be treated as an ATA/33 drive or, if older, whatever the drive actually is.

What is RAID?  A RAID or Redundant Array of Inexpensive Disks is a collection of disk drives that collectively act as a single storage system. In other words, two or more hard disk drives which are grouped together and appear as a single disk drive.  Or, in practice, it can also be two or more disk partitions grouped together and appear as a single partition/logical drive.  A partition or volume is just that, a demarcated and contiguous section a of a drive which appears like a drive--a logical drive.  There are six levels of RAID and the features of more than one level can combined in a RAID.  The HPT370 supports three flavors of RAID:

Stripping (RAID Level 0).   Provides performance (not redundant as implied in the acronym).  Data is evenly spread over identical drives.  That is, parts of file can be spread over more than one drive.  Data can be read and written in parallel.    Performance is very good.  Failure of any one disk in the array results in data loss.  This kind of RAID would be good for storing large files of temporary nature, but you sure wouldn't want to put you accounting package on one.

Mirroring (RAID level 1).   Provides redundancy.  Two drives duplicate each other identically.  If one drive fails, all of the data is available on the other one.  The read performance of mirrored drives can be increased through load balancing and elevator sorting (I won't go into elevator sorting here).  Simply put, when data is requested it is read from the least busy drive.  Put that accounting package on this one; I did.  But remember it is possible for Windows to "scribble" on a hard disk.  In this arrangement, a scribble on one drive is more than likely a "scribble" on both drives--mirrored garbage is garbage.

Striping/Mirroring (RAID 0+1).  Provides performance and redundancy.  Two sets of stripped drives (four drives in the case of the HP370) are mirrored.  This arrangement may be fast and redundant, but it is also expensive and complicated.

RAID can be done with software as well as hardware.  The configuration of our Windows NT file server is similar to RAID 1.  A critical partition on the primary drive is mirrored to a like partition on the secondary drive. We also did it quite a few years ago with two 340 MByte IDE hard disks and another IDE controller in a Novell file server with a 386 motherboard. SCSI drives have been used in mirrored configurations for many years.  Putting the IDE RAID function/chip on the motherboard is new.

Features.  The HPT370 provides two independent ATA channels at 256 Byte FIFO per ATA channel with concurrent PIO and bus master access.   Features include:

• Ultra DMA 100MB/S operation per ATA channel

• Supports up to 66MHz PCI bus Clock

• One PCI function supports two independent ATA channels

• ATA clock independent from PCI bus

• Optional between external 50MHz ATA bus clock or internal PLL

• 256 Bytes FIFO per ATA channel

• Supports all hard disks and ATAPI CD-ROM, DVD-ROM, CD-R, CD-RW, LS-120, MO, Tape and ZIP devices

• Easy Plug-and-Play feature

• Supports up to 8 ATA/ATAPI devices. (Coexist with on-board IDE)

• RAID function supported (RAID 0, 1, 0+1)

• Supports the most popular OS like Windows 95/98, Windows NT 4.0, Windows 2000 and Linux

• Supports booting function with Flash Memory interface

• Automatically fine tune to the best performance for each ATA/ATAPI device

• PIO and bus master access Concurrently (ATA port accessible during DMA transfer)

• Total IDE bus tri-state by software control and supports hotswap (Low signal Current)

• Reloadable PCI configuration using parallel EPROM or 2 wire serial EPROM (Loading address 0 for serial EPROM, loading address 400H for parallel EPROM)

• Small foot print 144-pin LQFP package

• Embedded serial resistors on chip for ATA spec.

So far, the HPT370 has appeared in the following Abit products:

• The Hot Rod 100 Pro--Ultra DMA IDE/RAID Controller Card.

• The Abit BX133-RAID Socket 370 Motherboard.  This board has four IDE interfaces and will support up to eight drives.

• The Abit KA7-100 Slot A Athlon Motherboard.  The KA&-100 has the HPT370 chip and does ATA/100, but is not advertised to have RAID capabilities.  Abit's FAQs state, "The RY BIOS also provides official support for the KA7-100's RAID capability, which boosts disk performance and data protection."  However, the released version is not available yet and I have heard that their are problems with the Beta version.  As Slot A boards are obsolete in my considered opinion, I have no plans to look into this board further.

Speculation about possible forthcoming motherboards with HPT370 chip.

• The Register has reported that Abit will introduce a RAID version of the KT7 Socket A Athlon motherboard in August.

• EpoX has experience and products with Highpoint UDMA controller chips.  The EP-USB66 ATA/66 Controller and USB Hub uses the HPT-366 chip and their recent Socket 370 EP-BX7+ motherboard uses an older, ATA/66 version of the Highpoint RAID controller, the HPT-368...

• Like EpoX EP-BX7+, the Iwill VD133Pro Socket 370 Motherboard includes the HTP368 RAID chip...

Bottom Line.  I would think that if the Abit ATA/100 RAID boards do well and there indications of that, and/or the EpoX and Iwill ATA/66 motherboards successful, EpoX and Iwill will shortly jump into the ring with ATA/100 RAID Socket A and 370 motherboards.  If all of these well-known motherboard manufactures sell RAID boards in large quantities, others will most certainly follow.  However, it still remains to be seen as to whether or not RAID is fad or becomes a "standard" feature on quality motherboards.

Larry

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Reference.

Adaptec RAID Guide

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