Dell PowerEdge MX750c EMC BIOS and UEFI Reference Guide - Page 15

Table 16. Integrated Devices details (continued) Option Description Internal SD Primary Card By default, the primary SD card is selected to be SD Card 1. If SD Card 1 is not present, then the controller selects SD Card 2 to be the primary SD card. OS Watchdog Timer If your system stops responding, this watchdog timer aids in the recovery of your operating system. When this option is set to Enabled, the operating system initializes the timer. When this option is set to Disabled (the default), the timer does not have any effect on the system. Empty Slot Unhide Enables or disables the root ports of all the empty slots that are accessible to the BIOS and operating system. This option is set to Disabled by default. Memory Mapped I/O above 4 GB Enables or disables the support for the PCIe devices that need large amounts of memory. Enable this option only for 64-bit operating systems. This option is set to Enabled by default. Memory Mapped I/O Base When set to 12 TB , the system maps the MMIO base to 12 TB. Enable this option for an operating system that requires 44-bit PCIe addressing. When set to 512 GB , the system maps the MMIO base to 512 GB, and reduces the maximum support for memory to less than 512 GB. Enable this option only for the 4 GPU DGMA issue. This option is set to 56 TB by default. Mezzanine Slot Disablement The Slot Disablement feature controls the configuration of mezzanine cards installed in the specified slots. Only mezzanine card slots that are present on your system are available for control. Serial Communication To view the Serial Communication screen, power on the system, press F2, and click System Setup Main Menu > System BIOS > Serial Communication. NOTE: The serial port is optional for the PowerEdge MX750c system. The Serial Communication option is applicable only if the serial COM port is installed in the system. Table 17. Serial Communication details Option Description Serial Communication Enables the serial communication options. Selects serial communication devices Serial Device 1in BIOS. BIOS console redirection can also be enabled, and the port address can be specified. The options available for System without serial COM port (DB9) are On without Console Redirection, On with Console Redirection, Off. This option is set to Off by default. Serial Port Address Enables you to set the port address for serial devices. This option is set to COM1 by default. NOTE: Every time the system boots, the BIOS syncs the serial MUX setting that is saved in iDRAC. The serial MUX setting can independently be changed in iDRAC. Loading the BIOS default settings from within the BIOS setup utility may not always revert the serial MUX setting to the default setting of Serial Device 1. External Serial Connector Enables you to associate the External Serial Connector to Serial Device 1 by using this option. NOTE: Every time the system boots, the BIOS syncs the serial MUX setting saved in iDRAC. The serial MUX setting can independently be changed in iDRAC. Loading the BIOS default settings from within the BIOS setup utility may not always revert this setting to the default setting of Serial Device 1. Pre-operating system management applications 15