Launched a couple of months ago, the latest model in Adaptec's range of SCSI cards is definitely not aimed at the home user. Instead, this PCI adapter is intended for use in very high-end workstations and entry-level to mid-range servers. What sets it apart from previous Adaptec SCSI cards is that it supports the latest Ultra2 SCSI standard, which provides for transfer rates up to a maximum of 80MB/sec.

Ultra2 SCSI works using a technique known as low-voltage differential, or LVD. This effectively increases the signal strength, allowing longer SCSI cables to be used than was previously possible. 80MB/sec is twice as fast as the previous SCSI best, and approximately four times as fast as the current maximum data transfer rate from an Ultra2 SCSI hard drive. That begs the obvious question "What's the point?", but the point is that up to four such drives can be connected to the AHA-2940U2W without suffering any performance degradation.

The card is equipped with a total of four interface connectors. Ultra2 SCSI connectors are present both externally and internally, while the other two internal sockets are for Ultra SCSI and Ultra-Wide SCSI devices, since mixing fast Ultra2 SCSI devices with slower Ultra SCSI ones would cause problems, usually resulting in all bus traffic running at the speed of the slowest device. Adaptec has cleverly incorporated firmware to ensure that, whatever device is connected to whichever connector, they all appear to be on the same SCSI bus, making for easier administration and maintenance.

A comprehensive collection of software drivers is provided with the card, including those for DOS, Windows 3.1x, Windows 95, Windows NT 4.0, Netware, OS/2 and Unix, and Adaptec also includes a good selection of interface cables. Apart from the introductory guide, however, all documentation is on CDROM.

Intended for use in high-end workstations and servers, this card should be able to cope comfortably with the bandwidth requirements of up to four Ultra2 SCSI hard drives. It's not cheap, but build quality and performance are sufficiently good that it should further Adaptec's reputation as the master of SCSI interface cards.