A central processing unit (CPU), also called a central processor, main processor, or just processor, is the most important processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, logic, controlling, and input/output (I/O) operations. This role contrasts with that of external components, such as main memory and I/O circuitry, and specialized coprocessors such as graphics processing units (GPUs).
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.
A superscalar processor is a CPU that implements a form of parallelism called instruction-level parallelism within a single processor. In contrast to a scalar processor, which can execute at most one single instruction per clock cycle, a superscalar processor can execute more than one instruction during a clock cycle by simultaneously dispatching multiple instructions to different execution units on the processor. It therefore allows more throughput than would otherwise be possible at a given clock rate. Each execution unit is not a separate processor, but an execution resource within a single CPU such as an arithmetic logic unit.
Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different forms of parallel computing: bit-level, instruction-level, data, and task parallelism. Parallelism has long been employed in high-performance computing, but has gained broader interest due to the physical constraints preventing frequency scaling. As power consumption by computers has become a concern in recent years, parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multi-core processors.
Simultaneous multithreading (SMT) is a technique for improving the overall efficiency of superscalar CPUs with hardware multithreading. SMT permits multiple independent threads of execution to better use the resources provided by modern processor architectures.
Hardware acceleration is the use of computer hardware designed to perform specific functions more efficiently when compared to software running on a general-purpose central processing unit (CPU). Any transformation of data that can be calculated in software running on a generic CPU can also be calculated in custom-made hardware, or in some mix of both.
A multi-core processor is a microprocessor on a single integrated circuit with two or more separate processing units, called cores, each of which reads and executes program instructions. The instructions are ordinary CPU instructions but the single processor 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 integrated circuit die or onto multiple dies in a single chip package. The microprocessors currently used in almost all personal computers are multi-core.
A network on a chip or network-on-chip is a network-based communications subsystem on an integrated circuit ("microchip"), most typically between modules in a system on a chip (SoC). The modules on the IC are typically semiconductor IP cores schematizing various functions of the computer system, and are designed to be modular in the sense of network science. The network on chip is a router-based packet switching network between SoC modules.
Scratchpad memory (SPM), also known as scratchpad, scratchpad RAM or local store in computer terminology, is an internal memory, usually high-speed, used for temporary storage of calculations, data, and other work in progress. In reference to a microprocessor, scratchpad refers to a special high-speed memory used to hold small items of data for rapid retrieval. It is similar to the usage and size of a scratchpad in life: a pad of paper for preliminary notes or sketches or writings, etc. When the scratchpad is a hidden portion of the main memory then it is sometimes referred to as bump storage.
Intel Teraflops Research Chip is a research manycore processor containing 80 cores, using a network-on-chip architecture, developed by Intel's Tera-Scale Computing Research Program. It was manufactured using a 65 nm CMOS process with eight layers of copper interconnect and contains 100 million transistors on a 275 mm2 die. Its design goal was to demonstrate a modular architecture capable of a sustained performance of 1.0 TFLOPS while dissipating less than 100 W. Research from the project was later incorporated into Xeon Phi. The technical lead of the project was Sriram R. Vangal.
TILE64 is a VLIW ISA multicore processor manufactured by Tilera. It consists of a mesh network of 64 "tiles", where each tile houses a general purpose processor, cache, and a non-blocking router, which the tile uses to communicate with the other tiles on the processor.
Tilera Corporation was a fabless semiconductor company focusing on manycore embedded processor design. The company shipped multiple processors in the TILE64, TILEPro64, and TILE-Gx lines.
A massively parallel processor array, also known as a multi purpose processor array (MPPA) is a type of integrated circuit which has a massively parallel array of hundreds or thousands of CPUs and RAM memories. These processors pass work to one another through a reconfigurable interconnect of channels. By harnessing a large number of processors working in parallel, an MPPA chip can accomplish more demanding tasks than conventional chips. MPPAs are based on a software parallel programming model for developing high-performance embedded system applications.
The SPARC64 V (Zeus) is a SPARC V9 microprocessor designed by Fujitsu. The SPARC64 V was the basis for a series of successive processors designed for servers, and later, supercomputers.
Manycore processors are special kinds of multi-core processors designed for a high degree of parallel processing, containing numerous simpler, independent processor cores. Manycore processors are used extensively in embedded computers and high-performance computing.
TILEPro64 is a VLIW ISA multicore processor manufactured by Tilera. It consists of a cache-coherent mesh network of 64 "tiles", where each tile houses a general purpose processor, cache, and a non-blocking router, which the tile uses to communicate with the other tiles on the processor.
The Single-Chip Cloud Computer (SCC) is a computer processor created by Intel Corporation in 2009 that features 48 distinct physical cores. These cores communicate through an architecture similar to a cloud computer data center. Cores are components of the processor responsible for executing instructions that enable the computer to function. The SCC resulted from an Intel project focusing on researching multi-core processors and parallel processing. Intel also aimed to explore the integration of designs and architecture from large cloud computer data centers into a single processing chip. The name "Single-chip Cloud Computer" reflects this concept.
Heterogeneous computing refers to systems that use more than one kind of processor or core. These systems gain performance or energy efficiency not just by adding the same type of processors, but by adding dissimilar coprocessors, usually incorporating specialized processing capabilities to handle particular tasks.
An AI accelerator, deep learning processor, or neural processing unit (NPU) is a class of specialized hardware accelerator or computer system designed to accelerate artificial intelligence and machine learning applications, including artificial neural networks and machine vision. Typical applications include algorithms for robotics, Internet of Things, and other data-intensive or sensor-driven tasks. They are often manycore designs and generally focus on low-precision arithmetic, novel dataflow architectures or in-memory computing capability. As of 2024, a typical AI integrated circuit chip contains tens of billions of MOSFET transistors.
A domain-specific architecture (DSA) is a programmable computer architecture specifically tailored to operate very efficiently within the confines of a given application domain. The term is often used in contrast to general-purpose architectures, such as CPUs, that are designed to operate on any computer program.
