IBM and Intel are joining forces in a multiyear project to design new super-slim "blade" servers, the companies plan to announce on Tuesday. The companies will meet to decide which models are needed and which company will design each system, said Tim Dougherty, director of blade server strategy at IBM. Both companies will get access to the blade designs that they decide in advance to share. However, each company also is free to design blade systems outside the arrangement that won't be shared. The first system that will fit into the deal will be IBM's BladeCenter systems, which Dougherty said will be announced by the end of September. Blade servers are thin models that squeeze side-by-side into a single enclosure like books in a bookshelf. Hewlett-Packard is the sole mainstream server maker to sell blade systems, but Dell Computer, IBM and Sun Microsystems each have their own designs. Blades have been a bright spot in an otherwise gloomy market for servers, the networked computers that run full time to handle jobs such as managing corporate e-mail or customer accounts. But designing blades involves balancing computing power against the risk of overheating, among other challenges. Where HP's current blades emphasise squeezing lots of low-end Pentium III processors into a small space, many in the industry are shifting their focus to higher-powered machines with dual Xeon processors. The IBM-Intel arrangement will revolve around these higher-end processors, said Phil Brace, marketing director for Intel's Enterprise Products Group. "The initial products are focused on Intel Xeon and Xeon MP," Brace said, referring to his company's midrange processors that work in two- and four-processor servers, respectively. "Itanium 2 solutions are on the horizon as well." It's difficult to squeeze processors into small spaces without overheating the computer, a problem that can cause data corruption and crashes. Putting higher-end processors such as Xeon and Itanium into small cabinets is trickier than cooler chips such as Intel's ultra-low voltage Pentium III chips. IBM sells full-featured servers, along with management software, services and other additions to make the systems useful. Intel, on the other hand, chiefly sells building block components such as motherboards that other companies can assemble and brand as their own servers. One blade pioneer is RLX Technologies, but the down economy and the loss of Internet enthusiasm that had led to the initial excitement about blades has left it struggling. Delivering Web pages to browsers is one task that's well-suited to low-power blades. RLX, which last month announced an additional $15m in funding, released its fourth-generation blade product Monday. The ServerBlade 1200i uses Intel Pentium III processors running at 1.2GHz. However, the faster speed comes with the consequence of lower density. While 24 of the earlier 800MHz 800i blades can fit into a 5.25-inch-tall enclosure, only 12 of the new 1200i fit in, RLX said.