The MPS setting in your BIOS is Multi Processor Setting (also shown as SMP in the bios). Enabling MPS tells your OS to look for Multiple Processors and which setting to use to support your processors. The default setting is usually 1.1 due to the fact that some OS's don't support 1.4. Disable MPS 1.4 support if your OS is giving you problems.
MPS version control is usually only valid for multiprocessor motherboards. It specifies the version of the Multiprocessor Specification (MPS) that the motherboard will use. The MPS is a specification by which PC manufacturers design and build x86 architecture systems with two or more processors.
MPS version 1.4 defines a standard for SMP hardware in which all processors are functionally identical, have equal status, and can communicate with one another. All of the processors in SMP hardware (hardware that complies with version MPS 1.4) share the same I/O subsystem and also the same memory space, which they access using the same memory addresses. A result of this is that all of the processors can execute one copy of an MP-enabled operating system.
MPS version 1.4 has added extended configuration tables, which improve support for multiple PCI bus configurations and improve future expandability. The 1.4 specifications is also required for a secondary PCI bus to work without the need for a bridge.
Most new versions of server operating systems will generally support MPS 1.4. If you are running a newer operating system that supports MPS, you should change the BIOS Setup to MPS 1.4 if your operating system supports version it. One should leave it as MPS 1.1 only if you are running older server operating systems.
