n Disk Subsystem Performance: Most servers implement SCSI disk subsystems. These allow more disks than the competing microcomputer IDE standard. However, performance varies significantly based on the SCSI standard, and some enhanced IDE-type disk drives now outperform SCSI transfer rates. In addition, the SCSI disks drives are more expensive than their IDE counterparts. Users have to weigh the immediate demands against the cost of upgrading the server later.

n Cache Memory: Cache memory built into a server can speed up its performance. With higher throughput, IT managers should look for additional cache memory that can be shared by processors. Some vendors bundle this secondary cache memory with their basic server package; others offer it as an option.

n Network Connection Configuration: Vendors of high-end (and some low-end servers) integrate an Ethernet port in the architecture of the server. This optimizes the transfer of data between the port and the processor. Other mid-range and low-end server vendors support Ethernet connections through a PCI slot. This approach adds flexibility and ensures that the Ethernet card can be upgraded as networks start to adopt higher-speed connections. IT managers should make sure that the server offers multiple slots for expansion.

n Management Software: Management utilities can simplify the cost of operating a server. Some products now support remote management functions using the Simple Network Management Protocol (SNMP). Many vendors also offer diagnostic utilities that monitor server performance and identify components that are behaving erratically. Knowing in advance that a component may fail allows IT managers to fix problems before they disrupt the network. Remote management and configuration functions also allow IT managers to maintain remote servers.

n Reliability Factor: Servers are designed for high reliability. Some vendors include redundant power supplies and fans to avoid total failure of the server. Several offer hot-swappable disk subsystems so that IS managers can service or upgrade the server without taking the system off-line. A few vendors also support hot-swappable power supplies and components, allowing a re-configuration or replacement without disrupting the network.

n Standards: Although in the low-end market the I2O committee released a standard for hot-swappable PCI cards, these will take time to reach acceptance. This means that IT managers must carefully review a vendor’s track records carefully and examine the underlying technologies before investing in a multiprocessor server.

n Basic Features: Many servers feature multiple, high-speed I/O buses that can be combined to operate in a burst mode. Many servers also come with massive amounts of memory to ensure that data moves without delays, and several share common memory areas to automatically balance processing loads. Processing speed, memory, and architecture are therefore very important issues.