MPMCenabled

MPMCenabled refers to the state in which a computer system is configured to operate using a Multi-Processor Multi-Channel (MPMC) memory topology. It is typically represented as a boolean flag within firmware, BIOS/UEFI settings, or operating system configuration. When enabled, the system activates memory interleaving and distributes memory access across multiple channels and CPU sockets, increasing potential memory bandwidth and parallelism on multi-socket servers and high-performance systems.

Context and scope: MPMC is characteristic of platforms that have two or more CPU sockets with independent memory controllers and multiple memory channels per socket. The MPMCenabled flag is commonly exposed in motherboard firmware as "Enable MPMC" or as part of NUMA-related options. In the operating system, enabling MPMC may be reflected by the presentation of multiple NUMA nodes and by scheduler policies that consider memory locality.

Implementation and requirements: Enabling MPMC requires hardware support (multi-socket CPUs with multi-channel memory controllers) and compatible memory modules. BIOS/UEFI firmwares provide the toggle; some systems enable MPMC by default. In software, a kernel boot parameter or module can activate or expose the topology to the scheduler and memory subsystem.

Performance and considerations: With MPMC enabled, workloads that benefit from parallel memory access, such as large in-memory databases or virtualization hosts, can see higher aggregate memory bandwidth. However, latency sensitivity and memory locality can become more complex to manage; misconfiguration can reduce performance or cause instability. Compatibility with specific CPUs, memory, and firmware versions may affect eligibility.

See also: NUMA, memory interleaving, multi-socket systems, memory channels, BIOS/UEFI configuration.