HP became the first of the major system vendors last week to launch four-processor server blades for applications in the data center.The HP ProLiant BL40p, a member of HP's Intel-based server blade family, is designed for enterprises, telecommunications companies and service providers. It is the first of the blades from IBM, Dell or HP to allow connection of either Fibre Channel storage-area networking (SAN) devices or network-attached storage. HP's other blades are single- and dual-processor designs for Web application deployment and midtier application server use.The company also introduced its dual-processor HP ProLiant BL20p blade server, which features SAN connectivity as well. It uses a 900-MHz Xeon processor, the same as the BL40p.HP's four-processor blades will start to encroach on the territory of Egenera, previously the only company to make four-processor blades. Egenera's blades since their introduction have been designed for data centers. Egenera's blades are much larger and come rigged to the gills with high-availability features.HP accomplishes the connection to the SAN via a mezzanine board which fits on the BL20p or a full-length host bus adapter used with the BL40p.The company claims that it owns 54% of the market for blade servers, much more than that of blade early-comer RLX Technologies. HP says it has shipped 15,000 blades.The HP ProLiant blade, like other HP blades, can be managed with HP ProLiant Essentials software, HP Insight Manager 7 and OpenView. It also works with HP's ProLiant Essentials Rapid Deployment Pack, which allows the automatic provisioning, configuration and installation of applications and operating systems.The HP BL40p will be available next month, starting at $9,000. The HP ProLiant BL10e starts at $1,860. It is available today.