In computing, multitasking is the concurrent execution of multiple tasks over a certain period of time. New tasks can interrupt already started ones before they finish, instead of waiting for them to end. As a result, a computer executes segments of multiple tasks in an interleaved manner, while the tasks share common processing resources such as central processing units (CPUs) and main memory. Multitasking automatically interrupts the running program, saving its state and loading the saved state of another program and transferring control to it. This "context switch" may be initiated at fixed time intervals, or the running program may be coded to signal to the supervisory software when it can be interrupted.
Non-uniform memory access (NUMA) is a computer memory design used in multiprocessing, where the memory access time depends on the memory location relative to the processor. Under NUMA, a processor can access its own local memory faster than non-local memory. NUMA is beneficial for workloads with high memory locality of reference and low lock contention, because a processor may operate on a subset of memory mostly or entirely within its own cache node, reducing traffic on the memory bus.
Symmetric multiprocessing or shared-memory multiprocessing (SMP) involves a multiprocessor computer hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all input and output devices, and are controlled by a single operating system instance that treats all processors equally, reserving none for special purposes. Most multiprocessor systems today use an SMP architecture. In the case of multi-core processors, the SMP architecture applies to the cores, treating them as separate processors.
Multiprocessing is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to the ability of a system to support more than one processor or the ability to allocate tasks between them. There are many variations on this basic theme, and the definition of multiprocessing can vary with context, mostly as a function of how CPUs are defined.
Originally, the word computing was synonymous with counting and calculating, and the science and technology of mathematical calculations. Today, "computing" means using computers and other computing machines. It includes their operation and usage, the electrical processes carried out within the computing hardware itself, and the theoretical concepts governing them.
In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit central processing units (CPU) and arithmetic logic units (ALU) are those that are based on processor registers, address buses, or data buses of that size. A computer that uses such a processor is a 64-bit computer.
x86-64 is a 64-bit version of the x86 instruction set, first announced in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging mode.
In computer operating systems, memory paging is a memory management scheme by which a computer stores and retrieves data from secondary storage for use in main memory. In this scheme, the operating system retrieves data from secondary storage in same-size blocks called pages. Paging is an important part of virtual memory implementations in modern operating systems, using secondary storage to let programs exceed the size of available physical memory.
NetWare is a discontinued computer network operating system developed by Novell, Inc. It initially used cooperative multitasking to run various services on a personal computer, using the IPX network protocol.
Aviion was a series of computers from Data General that were the company's main product from the late 1980s until the company's server products were discontinued in 2001. Earlier Aviion models used the Motorola 88000 CPU, but later models moved to an all-Intel solution when Motorola stopped work on the 88000 in the early 1990s. Some versions of these later Intel-based machines ran Windows NT, while higher-end machines ran the company's flavor of Unix, DG/UX.
Unix System V is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, and 4. System V Release 4 (SVR4) was commercially the most successful version, being the result of an effort, marketed as Unix System Unification, which solicited the collaboration of the major Unix vendors. It was the source of several common commercial Unix features. System V is sometimes abbreviated to SysV.
Windows NT 3.1 is the first major release of the Windows NT operating system developed by Microsoft, released on July 27, 1993.
HPE Integrity Servers is a series of server computers produced by Hewlett Packard Enterprise since 2003, based on the Itanium processor. The Integrity brand name was inherited by HP from Tandem Computers via Compaq.
A multi-core processor (MCP) is a microprocessor on a single integrated circuit (IC) with two or more separate central processing units (CPUs), called cores to emphasize their multiplicity. Each core reads and executes program instructions, specifically ordinary CPU instructions. However, the MCP can run instructions on separate cores at the same time, increasing overall speed for programs that support multithreading or other parallel computing techniques. Manufacturers typically integrate the cores onto a single IC die, known as a chip multiprocessor (CMP), or onto multiple dies in a single chip package. As of 2024, the microprocessors used in almost all new personal computers are multi-core.
In computing, an input–output memory management unit (IOMMU) is a memory management unit (MMU) connecting a direct-memory-access–capable (DMA-capable) I/O bus to the main memory. Like a traditional MMU, which translates CPU-visible virtual addresses to physical addresses, the IOMMU maps device-visible virtual addresses to physical addresses. Some units also provide memory protection from faulty or malicious devices.
The ES7000 is Unisys's x86/Windows, Linux and Solaris-based server product line. The "ES7000" brand has been used since 1999, although variants and models within the family support various processor and bus architectures. The server is marketed and positioned as a scale-up platform where scale-out becomes inefficient. Typically the ES7000 is utilized as a platform for homogeneous consolidation, large databases, Business Intelligence, Decision Support Systems, ERP, virtualization, as well as large Linux application hosting.
LynxSecure is a least privilege real-time separation kernel hypervisor from Lynx Software Technologies designed for safety and security critical applications found in military, avionic, industrial, and automotive markets.
QPACE 2 is a massively parallel and scalable supercomputer. It was designed for applications in lattice quantum chromodynamics but is also suitable for a wider range of applications..
A multiprocessor system is defined as "a system with more than one processor", and, more precisely, "a number of central processing units linked together to enable parallel processing to take place".
