IBM HS21 User Guide - Page 20

v I/O expansion The blade server has connectors on the system board for optional expansion cards for adding more network communication capabilities to the blade server. v Large system memory The blade server system board supports up to 16 GB of system memory. The memory controller provides support for up to four industry-standard fully-buffered double-data rate (FB-DDR2), PC2-5300, ECC SDRAM registered x4 (Chipkill™) DIMMs installed on the system board. The controller is able to support additional memory DIMMs that are installed in an optional expansion unit. For the most current list of supported DIMMs, see the ServerProven® list at http://www.ibm.com/servers/eserver/serverproven/compat/us/. v Light path diagnostics Light path diagnostics provides light-emitting diodes (LEDs) to help you diagnose problems. For more information, see the Problem Determination and Service Guide. v PCI Express PCI Express is a serial interface that is used for chip-to-chip interconnect and expansion adapter interconnect. With the blade expansion connector you can add optional I/O and storage devices. v Power throttling Each blade server is powered by two BladeCenter redundant power-supply modules. By enforcing a power policy known as power-domain oversubscription, the BladeCenter unit can share the power load between two power modules to ensure sufficient power for each device in the BladeCenter unit. This policy is enforced when the initial power is applied to the BladeCenter unit or when a blade server is inserted into the BladeCenter unit. The following settings for this policy are available: - Redundant without performance impact - Redundant with performance impact - Nonredundant You can configure and monitor the power environment by using the management module. For more information about configuring and using power throttling, see the management-module documentation or http://www.ibm.com/systems/support/. Reliability, availability, and serviceability features Three of the most important features in server design are reliability, availability, and serviceability (RAS). These RAS features help to ensure the integrity of the data that is stored in the blade server, the availability of the blade server when you need it, and the ease with which you can diagnose and correct problems. The blade server has the following RAS features: v Advanced Configuration and Power Interface (ACPI) v Automatic error retry or recovery v Automatic server restart v Built-in monitoring for temperature, voltage, hard disk drives. v Chipkill memory v Customer support center 24 hours per day, 7 days a week1 v Customer-upgradeable basic input/output system (BIOS) code and diagnostics v Diagnostic support of Ethernet controllers 1. Service availability will vary by country. Response time will vary depending on the number and nature of incoming calls. 8 BladeCenter HS21 Type 8853: Installation and User's Guide