The main classes of modern parallel computers Systems with non-uniform memory access (NUMA)

Architecture

The system consists of homogeneous basic modules (cards) consisting of a small number of processors and a memory block. Modules are integrated using a high-speed switch. A single address space is supported, access to remote memory is supported by hardware, i.e. to the memory of other modules. At the same time, access to local memory is several times faster than remote one. In case the coherence of caches throughout the system is supported by hardware (usually this is so), talk about the c-NUMA architecture (cache-coherent NUMA)

Examples

HP HP 9000 V-class in SCA configurations, SGI Origin2000, Sun HPC 10000, IBM / Sequent NUMA-Q 2000, SNI RM600.HP 9000 V-classOrigin2000HPC 10000 NUMA-Q 2000RM600

Scalability

The scalability of NUMA-systems is limited by the amount of address space, the capabilities of the hardware supporting the coherence of caches and the operating system's ability to manage a large number of processors. Currently, the maximum number of processors in NUMA systems is 256 (Origin2000).

operating system

Usually the whole system runs under the control of a single OS, as in SMP. But there are also options for the dynamic "division" of the system, when individual "partitions" of the system are running under different operating systems (for example, Windows NT and UNIX in NUMA-Q 2000) .SMP

Programming model

Same as SMP.SMP