NUMA node
also: NUMA
A NUMA node is a distinct memory and CPU grouping in a Non-Uniform Memory Access system, where each node has its own local memory with faster access than memory on remote nodes.
NUMA (Non-Uniform Memory Access) divides modern multi-socket systems into nodes, each containing CPUs and attached memory. A process running on a CPU in a NUMA node accesses its local memory much faster than memory on another node, creating performance asymmetry unlike older Uniform Memory Access (UMA) systems.
On a 2-socket server, for example, socket 1 with 4 CPUs and 64GB of RAM forms one NUMA node, while socket 2 forms another. A process on node 0 can read/write node 0's memory in ~100 nanoseconds but accesses node 1's memory with ~150+ nanosecond latency.
Linux tools like numactl and numa_stat help inspect and control NUMA topology. You can bind processes to specific nodes with numactl --membind=1 myprogram to keep memory access local and avoid costly remote accesses that hurt performance.