Many enterprise data centers use industry-standard 19-inch racks for data and communication equipment storage. So it's only natural that servers have made their way on to racks, enabling similar cable management, equipment density and manageability.

In our search for servers that can function in the data center or as a departmental server, we tested four dual-processor Pentium Pro servers specifically designed for rack-mounting: ALR's Rack-Mountable Revolution 6X6, ChatCom's ChatterBox, Compaq Computer Corp.'s ProLiant 5500R 6/200 and Micron Electronics' NetFrame 9016. We evaluated front-panel access, serviceability and remote management features, and we looked for fault-tolerance capabilities and decent scalability.

To view the Report card.We chose to test systems that appear on Microsoft Corp. and Novell hardware compatibility lists. All servers shipped with a Fast Ethernet NIC of the vendor's choice. We required a very large memory capacity because of rocketing memory requirement trends. Finally, we focused on suitability for rack-mounting and serviceability because these factors distinguish rack-mounted servers from ordinary servers that live on a rack shelf.

It's important to note the distinction between rack-mountable and cabinet-mountable servers. The systems we tested, with the exception of ChatCom's, were installed on our data center's existing single-faced Hubble 19-inch racks. All but the NetFrame 9016 were better-suited for cabinet-mounting rather than single-faced racks, so we used cantilever shelves for support. ChatCom's ChatterBox came with its own cabinet, but we had to leave headroom above the systems to service ALR's and Compaq's servers.

Micron's NetFrame 9016 merited our Editor's Choice award because it is extremely well-designed for the rack and exhibited excellent fault-tolerant features. Overall, however, its performance was lackluster because of the system's standard SCSI controller and non-Ultra hard drives. (The other systems we tested included cached RAID controllers and Ultra-SCSI drives.) Nevertheless, NetFrame's impressive features, coupled with its strong management capabilities, made it our top pick.

Finishing second in our survey, ALR's Rack-Mountable Revolution 6X6 demonstrated optimal scalability, performance and management. But we were not as impressed with its rack design. Compaq's ProLiant 5500R 6/200 server garnered our Best Value award because it offers the most bang for the buck. It sports automatic server recovery, versatile software and front-panel management, and excellent performance. But in general, the Compaq ProLiant lacked serviceability.

Micron Electronics NetFrame 9016
Micron's NetFrame 9016 dazzled us with its fault-tolerance and serviceability. It is--far and away--the most versatile rack-mounted server we've ever seen. Each component slides into the front of the frame, and all plugging--from power cords to SCSI to Ethernet--occurs in the front. The server's depth is relatively shallow, and its low center of gravity makes it well-suited for a single-faced rack.

NetFrame 9016's multiple I/O card cages are an impressive innovation. Each cage is hot-swappable, a notable feature among the servers we tested. Thanks to the bundled NetFrame MultiSpan Software, you can set each card cage, called a Fault Isolation Canister (FIC), offline when a NIC or SCSI controller fails. This will let a technician remove it and swap out the board while the system is running. No other server we tested offered this functionality. (Versions of the MultiSpan Software for Microsoft Windows NT and Novell IntranetWare ship with the server.)