IBM 79717au User Guide - Page 21

v Large system memory Depending on the blade server model, it supports up to 16 GB (single-width models) or 32 GB (double-width models) of system memory. The memory controller in each microprocessor provides support for up to four industry-standard VLP, DDR2, ECC SDRAM registered x4 (Chipkill) or x8 (non-Chipkill) DIMMs. 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 fully-serial interface that can be used for universal connectivity for use as a chip-to-chip interconnect, I/O interconnect for adapters, and an I/O attachment point to Gigabit-networking devices. Using an expansion unit, you can add additional LAN interfaces. 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 efficient 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. 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/bladecenter/ and click 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, and hard disk drives v Chipkill™ memory for x4 DIMMs 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 v ECC memory v ECC protection on the L2 cache v Error codes and messages v Failover Ethernet support v Hot-swap drives on optional SAS storage expansion unit v Light path diagnostics feature v Microprocessor built-in self-test (BIST) during power-on self-test (POST) v Microprocessor presence detection 1. Service availability will vary by country. Response time will vary depending on the number and nature of incoming calls. Chapter 1. Introduction 9