Chapter 3. Hardware configuration 121 The DIMMs must be added in matched pairs, that is, two at a time, and theymust also match the equivalent pair of DIMMs on the matching memory cardon the other power bus. A minimum of 4 GB of memory must be installed in the server for hot-addmemory to be available. Additionally, for 32-bit operating systems, thePhysical Address Extension (PAE) mode has to be enabled to take advantageof the additional memory.For details about performing a hot-add operation, and restrictions, see IBM:System x3850 M2 and System x3950 M2 User’s Guide:http://www.ibm.com/support/docview.wss?uid=psg1MIGR-50730293.2.6 Memory configuration in BIOSThe BIOS includes settings related to processor and operating systemconfiguration and performance purposes. You can adjust the settings.To access the settings and configure the memory subsystem in the server’sBIOS setup:1. Power on or reboot the system.2. Press F1 during system startup, when prompted.3. From the Main Menu window, choose Advanced Setup.4. Select Memory Options. The Memory Settings selection menu opens, asshown in Figure 3-15.Figure 3-15 Memory BIOS settingsMemory Card 1Memory Card 2Memory Card 3Memory Card 4Memory Array Setting [ HPMA (High Performance Memory Array ]Initialization Scrub Control [ Scrub on every boot ]Run Time Scrub Rate [ Default scrub rate ]Memory Settings
