Overview
In the world of Wintel-based Servers (a/k/a PC Servers), the types of machines offered are as varied as the applications for which they are used. Although it is risky to apply terms too broadly, we can break the server market into six segments, and provide a guide to the features and characteristics of each. (There are other ways the market can be segmented - we have chosen this because it more "accessible" to the general user.)
In general, servers are segmented by the size of the user population they serve - from small "Mom and Pop" shops up to large companies with thousands of employees. However, there are exceptions, which will also be explored herein.
Segments
The size-related segments we have defined, from smallest population served to largest, are:
All of the above segments are for general-purpose servers - those which try to have a broad mix of features and functions, to appeal to the widest range of customers The sixth segment is relatively new, only a few years old. Rather than being defined by number of users, it is categorized in terms of what it does, not whom it serves. This segment is variously referred to as "Single-Function Server", "Server Appliance", "Information Appliance", "Thin Server", and "Task Server" - each designation having slightly different connotations. For simplicity, we will lump the sub-genres together and refer to the general product group as "Appliance Server". This segment (for both Wintel and Unix/Linux-based systems) is predicted to grow to $8 Billion by 2003. [Source: IDC].
Segment Definitions
For the purposes of this document, we will use the definitions below. (Over time, these definitions have changed, and will continue to change, and we expect that segments will consolidate.) Refer to Graph 1 for approximate user quantity vs. segment map.
Correlation Factors
Now that we have defined the segments, what can we expect to get for our money, and what is the correlation between market segment and feature/function set? In other words, on which areas (e.g., processing power, reliability, price) can we expect each of the segments to focus?
The features and functions that matter in servers are separated into two general groups, which we can call "Goals" (which are more strategic in nature) and "Features" (which are more tactical in nature). In other words, "Goals" are the overarching categories, and "Features" are the implementation methods or physical constructs by which the goals are achieved.
The factors listed in Table 1 are a sampling of some of the more important ones; there are others that users will find relevant to their particular situation or need. Different users will have different requirements, and thus factor weightings will vary by user, so the relative "weight" of each factor is not part of Table 1.
Customers can use the Table, in concert with other sizing tools (usually based on the software or infrastructure, such as SAP R/3 or Microsoft Exchange), to help them determine which class of server will be best suited to their needs.
Table 1 shows the correlation of the various Goals and Features to the defined segments.
Table 1
Factor Definitions :
Performance/Power: Computational (or similar) power, the ability to perform a large number of operations or to handle a large workload.
High Reliability: The ability to run without a non-recoverable failure for long periods of time. (Note that "reliability" is a goal for all classes of server. The term "high reliability" is used because different server classes require different levels of reliability.
Price: Base system price, or price with a modest complement of features added. Total Cost of Ownership (TCO): An amalgam of fully-configured system price, installation/setup/training costs, infrastructure costs, downtime costs, and other factors.
Flexibility: The ability of the server to be reconfigured for disparate tasks/functionality, as needed by the user. Service/support: Related to availability and reliability, maintainability, and ease-of-use considerations.
High CPU qty.: Whether a server can support four, eight, or more CPUs
Storage (internal): The storage capacity, both in terms of raw space (i.e. how many gigabytes) and number of disk drives, a server can support inside the chassis.
Redundancy: Whether a given component (e.g. fan, power supply, network interface card, disk drive) has a backup and a failover mechanism. Redundancy is a method for improving system reliability/availability.
Hot Swap/Maintainability: The ability to remove and replace a component (e.g. fan, disk drive, power supply) without having to shut down the system or cause processing functions to stop.
Outlook
As the server market consolidates, market/product segment distinctions - especially at the low end - will blur. We believe that within 12-24 months, there will be only three size-related segments (Entry/Workgroup, Department, and Enterprise) plus the general class of Appliance servers. As the number of segments decreases, the distinction between them will increase. However, certain patterns will be maintained, such as Enterprise Servers needing to be extremely reliable. Customers should keep these factors in mind as they move toward future server purchases.