Historically, servers only assumed the form factor of a re-purposed desktop computer or rack-mountable appliance. These servers utilized high-quality components and leverage additional memory and hard disk capacity. Now server form factors are evolving into single PC cards that can be plugged into a chassis as a single module.

Bladed servers stack numerous independent lower-end servers within a single chassis. Chassis can accept anywhere from eight to 24 blades. Each blade is an independent system with its own memory, processor and network connection. Due to their compact size, multiple blade servers can be placed in a single server rack or enclosure, allowing numerous systems to share electricity and HVAC resources.

Gartner DataQuest (dataquest.com) predicts that worldwide server blade shipments will increase from 84,410 units in 2002 to more than one million in 2006. The IT research firm anticipates that revenue from server blades will reach at least $1.2 billion during this time period. Blades are thus becoming the one major segment of the server market that is experiencing escalating growth.

The popularity and fast growth of the blade server can be attributed to cost-savings that the device accrues to its users, especially hosting firms and service providers. Because more than 250 blade servers can be effectively placed into a single rack, it is possible for hosting firms with data center operations to quadruple their hosting capacity with the devices. By comparison, most of today's low-end servers have only a single computer in one enclosure, allowing only one 42 systems to fit in an industry-standard rack.

Because blade servers are small, consume less power and generate less heat than an average server, they are emerging as an ever-popular option for niche Web hosting services. With the cost of data center space at approximately $300 per square foot and with energy costs increasing throughout continental North America due to deregulation, blade servers have become the de facto standard for increasing data center profitability.

The systems are typically used as Web servers and caching servers that deliver Web pages to Internet browsers, SSL servers for encrypted communication, and streaming servers for audio and video transmissions. Most hosting companies and service providers appreciate the devices because they are easy to install and employ dedicated software that improves their administration, performance and reliability. The devices are also increasingly being utilized as firewall devices and to increase capacity in corporate data centers.

Blade severs are excellent devices for hosting companies with large existing data center deployments who want to capitalize upon existing PCI expansion space. The inclusion of a single blade allows a hosting company to double its computing power or hosting offering, utilizing the same amount of physical space. The main disadvantage concerning PCI-based blade servers is that the processors are usually not as robust as traditional high-end servers. This factor limits the use of the server to functions such as low-end Web hosting.

While blade severs have the capacity to serve streaming video and other demanding applications, often the emerging technology is used for back up or storage purposes. Lower-end models usually depend on server or operating system virtualization, causing the server to run much slower than traditional equipment.

It is thus incumbent upon a reseller to determine whether a hosting company is utilizing blade servers for mission-critical deployments and whether those servers can accommodate demanding applications.

Resellers who operate their own equipment might want to consider utilizing blade servers as an effective technology to add firewall or other security specific capacities to their colocated equipment.