Ultra 160 Adapters Ship--Finally.

SCSI has been through a wide range of well-documented twists and turns. With origins going back more than 100 dog years and probably more computer years, SCSI can fairly claim that it descended from the SASI (Shugart Associates System Interface) specification developed in the mid '80s.

Along the way, a proposed SCSI implementation that provided higher throughput speeds, more distance, and an expanded number of connections became Fibre Channel. In 1998, a group of companies developed a subset of SCSI-3 that was at that time called Ultra-160/M. Ultra 160/M included a subset of 3 of the 5 original features of SCSI-3 with a 160MB/sec throughput speed of supported devices. The M, which was touted as an important feature, in Ultra 160/M stood for Manageability. The idea presented was that 160/M would simplify the task of managing devices on the SCSI bus.

Recent versions of the specification have dropped the /M. The manageability component was apparently not a favorite part of the name and, for uniformity, all companies supporting 160/M decided to drop it in favor of the name Ultra 160.

Adaptec showed initial 160/M host bus adapters running on prototype hard drives behind closed doors at Fall Comdex in November 1998. The promise of a timely release was not met. Throughout 1999, Adaptec's 160 demonstration, showing multiple concurrent streaming video streams continued--but without a release date for the host bus adapters. Plans for announcement that the adapters shipped were made for a late summer. These plans were scrubbed.

On January 10, 2000, Adaptec announced that it had started shipping its Ultra 160 adapters to the channel. The new cards promise twice the performance of the previous line of cards--with a maximum throughput of 160MB/sec on each channel. Four boards were announced, ranging from the low-end, single channel 19160, up the two channel 39160. The basic differences are the support for one or two channels on card support for 50 pin Ultra, 68 pin Ultra, or LVD support, or external connections. Additionally, the cards are differentiated by support for 32 bit PCI or 64 bit PCI.

Standard cabling used for previous generation SCSI controllers will work with the new Ultra 160 host bus adapters, according to Adaptec. Additionally, the new cards are said to be priced at price points that are comparable to the previous generation HBAs.

The new cards may be attractive replacements for integrators who are adding hard drives that support the Ultra 160 specification. Additionally, for new systems, installing the new card should be a no brainer, providing support for faster drives (or more drives on a channel) than equally priced, last generation controllers. In addition to providing higher performance, which may be especially important when as many as 15 attached drives are all vying for bandwidth, the Ultra 160 specification adds Cyclic Redundancy Checking (CRC) to reduce data errors and also includes domain validation, a feature that tunes the SCSI controller's performance to match the actual throughput of the drives on the bus.