What is CMOS setup primarily used for?

CMOS setup is primarily used to configure system BIOS settings. This configuration includes various important parameters for the computer's hardware, such as the boot sequence, system time and date, hardware configuration, and device settings. When the computer starts up, it accesses the CMOS (Complementary Metal-Oxide-Semiconductor) to retrieve these settings stored in a small battery-powered memory. This allows for the customization of how the computer interacts with its hardware components and the operating system.

The other options, while relevant to computer functions, do not accurately describe the primary purpose of CMOS setup. For instance, CMOS does not store volatile data; it mainly holds non-volatile BIOS settings that retain information even when the power is off. The setup is not designed specifically to enhance overall speed or facilitate graphics processing, as those aspects are determined by the CPU, RAM, and graphic cards among others.