Since the beginning of 2001, companies large and small have touted the emergence of blades in the computer market. Rather than sitting horizontally in a rack or on a desk, blades slide vertically like record albums into a specialised rack that contains all the wiring necessary to hook the computers into the network. Although some companies are using the blade idea to replace desktops, most companies have applied the blade concept to servers. The architectural change brings a host of benefits, according to analysts and computer executives. For one thing, more blades can be fit into a centralized computer room, which economizes on real estate expenses. The increased density comes in part because blades share many components, which are actually incorporated into the rack. In the BladeCenter system, for instance, 16 blades rely on four power supplies and share CD-ROM drives. Ordinarily, each server would come with an individual power supply and drive. The amount of cable required to hook up these servers is reduced by 83 percent, said Mark Shearer, vice president of blade servers at IBM. The Fibre Channel switch for connecting the servers to a storage system is also incorporated into the rack. Typically, it comes as a separate piece of equipment. Even more important, corporate computer departments become easier to manage. Repurposing a server -- that is, using it as a Web server one hour and as an email server the next -- is also much easier and quicker with blades because of complementary software-management tools. "It takes you something like 10 minutes to reposition another OS (operating system)," Freund said. Swapping out damaged components or blades takes far less time too. Honing blades
Even though blades have been on the market only about 18 months, the basic architecture has already changed. Initially, companies like RLX Technologies incorporated notebook processors into their blade racks to cut down on power consumption and reduce heat. This allowed the company to pack several hundred computers into a six-foot rack. Pure density, however, wasn't a huge hit. IBM sold RLX servers for a while but dropped them after low sales: customers wanted the same sort of performance they got with regular servers, even if it reduced maximum density. "The solutions that are out there don't let you do enterprise workloads," said Shearer. Following this path, IBM will begin to incorporate technologies found in its other lines into the BladeCenter. Four-processor Xeon blades will come out in the first quarter of next year, while blades for Itanium and Power 4 chips, usually used in IBM's most expensive machines, will come later. The company will also work with software developers and other hardware manufacturers in its Blade Server Alliance Program to tune or codevelop other products for BladeCenter. Microsoft and Red Hat, for instance, are currently validating software to work smoothly on BladeCenter. IBM is also working with Cisco and Nortel, alliances that could lead to Cisco-branded blades for the rack. All of these different blades will also fit into the same rack, said IBM's Benck. The company's services and leasing group is also concocting programs to ease adoption, Big Blue's Shearer added. In true IBM fashion, the BladeCenter also features a certain amount of flourishes, noted Freund. Each blade comes encased in a sheet metal sleeve that allows fans to create even channels of air for cooling. "If anything, it is overdesigned right now, so that in the future when you have more powerful processors from Intel or whomever, it can accommodate it," Illuminata's Freund said. HP follows a similar ethos. Its latest blade servers are only slightly more dense than traditional rack-mounted servers, but the company will be able to fit two- and four-processor blades into the rack. HP says it is selling 1,800 blades per month. In IBM's system, 14 blades fit into a single chassis and six chassis piled on top of one another fill an entire rack. A 14-blade chassis complete with blades starts at $89,240, while the rack itself sells for $64,000.
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