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111-559: Graphics Core Next ( GCN ) is the codename for a series of microarchitectures and an instruction set architecture that were developed by AMD for its GPUs as the successor to its TeraScale microarchitecture. The first product featuring GCN was launched on January 9, 2012. GCN is a reduced instruction set SIMD microarchitecture contrasting the very long instruction word SIMD architecture of TeraScale. GCN requires considerably more transistors than TeraScale, but offers advantages for general-purpose GPU (GPGPU) computation due to

222-497: A marketing buzz for the project). Still others (such as Microsoft ) discuss code names publicly, and routinely use project code names on beta releases and such, but remove them from final product(s). In the case of Windows 95, the code name "CHICAGO" was left embedded in the INF File structure and remained required through Windows Me. At the other end of the spectrum, Apple includes the project code names for Mac OS X as part of

333-453: A "B", cargo aircraft with a "C". Training aircraft and reconnaissance aircraft were grouped under the word "miscellaneous", and received "M". The same convention applies to missiles, with air-launched ground attack missiles beginning with the letter "K" and surface-to-surface missiles (ranging from intercontinental ballistic missiles to antitank rockets) with the letter "S", air-to-air missiles "A", and surface-to-air missiles "G". Throughout

444-482: A "pivotal" role in Soviet air-strategy. Code names were adopted by the following process. Aerial or space reconnaissance would note a new aircraft at a Warsaw Pact airbase. The intelligence units would then assign it a code name consisting of the official abbreviation of the base, then a letter, for example, "Ram-A", signifying an aircraft sighted at Ramenskoye Airport . Missiles were given designations like "TT-5", for

555-660: A "wavefront" consists of 64 threads, and in all Nvidia GPUs, a "warp" consists of 32 threads. AMD's solution is to attribute multiple wavefronts to each SIMD-VU. The hardware distributes the registers to the different wavefronts, and when one wavefront is waiting on some result, which lies in memory, the CU Scheduler assigns the SIMD-VU another wavefront. Wavefronts are attributed per SIMD-VU. SIMD-VUs do not exchange wavefronts. A maximum of 10 wavefronts can be attributed per SIMD-VU (thus 40 per CU). AMD CodeXL shows tables with

666-462: A CPU include the arithmetic–logic unit (ALU) that performs arithmetic and logic operations , processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that orchestrates the fetching (from memory) , decoding and execution (of instructions) by directing the coordinated operations of the ALU, registers, and other components. Modern CPUs devote

777-486: A CPU may also contain memory , peripheral interfaces, and other components of a computer; such integrated devices are variously called microcontrollers or systems on a chip (SoC). Early computers such as the ENIAC had to be physically rewired to perform different tasks, which caused these machines to be called "fixed-program computers". The "central processing unit" term has been in use since as early as 1955. Since

888-475: A Heterogeneous-compute Interface for Portability (HIP) tool for porting CUDA applications to the aforementioned common C++ model. As of July 2017, the Graphics Core Next instruction set has seen five iterations. The differences between the first four generations are rather minimal, but the fifth-generation GCN architecture features heavily modified stream processors to improve performance and support

999-673: A Shader Engine is the Graphics Command Processor, the 8 ACEs, the L2 cache and memory controllers as well as the audio and video accelerators, the display controllers, the 2 DMA controllers and the PCIe interface. The A10-7850K "Kaveri" contains 8 CUs (compute units) and 8 Asynchronous Compute Engines for independent scheduling and work item dispatching. At AMD Developer Summit (APU) in November 2013 Michael Mantor presented

1110-402: A cache had only one level of cache; unlike later level 1 caches, it was not split into L1d (for data) and L1i (for instructions). Almost all current CPUs with caches have a split L1 cache. They also have L2 caches and, for larger processors, L3 caches as well. The L2 cache is usually not split and acts as a common repository for the already split L1 cache. Every core of a multi-core processor has

1221-400: A code from the control unit indicating which operation to perform. Depending on the instruction being executed, the operands may come from internal CPU registers , external memory, or constants generated by the ALU itself. When all input signals have settled and propagated through the ALU circuitry, the result of the performed operation appears at the ALU's outputs. The result consists of both

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1332-461: A data word, which may be stored in a register or memory, and status information that is typically stored in a special, internal CPU register reserved for this purpose. Modern CPUs typically contain more than one ALU to improve performance. The address generation unit (AGU), sometimes also called the address computation unit (ACU), is an execution unit inside the CPU that calculates addresses used by

1443-458: A dedicated L2 cache and is usually not shared between the cores. The L3 cache, and higher-level caches, are shared between the cores and are not split. An L4 cache is currently uncommon, and is generally on dynamic random-access memory (DRAM), rather than on static random-access memory (SRAM), on a separate die or chip. That was also the case historically with L1, while bigger chips have allowed integration of it and generally all cache levels, with

1554-564: A global clock signal. Two notable examples of this are the ARM compliant AMULET and the MIPS R3000 compatible MiniMIPS. Rather than totally removing the clock signal, some CPU designs allow certain portions of the device to be asynchronous, such as using asynchronous ALUs in conjunction with superscalar pipelining to achieve some arithmetic performance gains. While it is not altogether clear whether totally asynchronous designs can perform at

1665-460: A hundred or more gates, was to build them using a metal–oxide–semiconductor (MOS) semiconductor manufacturing process (either PMOS logic , NMOS logic , or CMOS logic). However, some companies continued to build processors out of bipolar transistor–transistor logic (TTL) chips because bipolar junction transistors were faster than MOS chips up until the 1970s (a few companies such as Datapoint continued to build processors out of TTL chips until

1776-522: A lot of semiconductor area to caches and instruction-level parallelism to increase performance and to CPU modes to support operating systems and virtualization . Most modern CPUs are implemented on integrated circuit (IC) microprocessors , with one or more CPUs on a single IC chip. Microprocessor chips with multiple CPUs are called multi-core processors . The individual physical CPUs, called processor cores , can also be multithreaded to support CPU-level multithreading. An IC that contains

1887-411: A memory management unit, translating logical addresses into physical RAM addresses, providing memory protection and paging abilities, useful for virtual memory . Simpler processors, especially microcontrollers , usually don't include an MMU. A CPU cache is a hardware cache used by the central processing unit (CPU) of a computer to reduce the average cost (time or energy) to access data from

1998-459: A number that identifies the address of the next instruction to be fetched. After an instruction is fetched, the PC is incremented by the length of the instruction so that it will contain the address of the next instruction in the sequence. Often, the instruction to be fetched must be retrieved from relatively slow memory, causing the CPU to stall while waiting for the instruction to be returned. This issue

2109-672: A part of the third generation of GCN, adding high-quality video scaling and the HEVC (H.265) codec. VCE 4.0 was part of the Vega architecture, and was subsequently succeeded by Video Core Next . In a preview in 2011, AnandTech wrote about the unified virtual memory, supported by Graphics Core Next. Some of the specific HSA features implemented in the hardware need support from the operating system's kernel (its subsystems) and/or from specific device drivers. For example, in July 2014, AMD published

2220-484: A set of 64 4-byte numbers. On the vector registers, every operation is done in parallel on the 64 numbers. which correspond to 64 inputs. For example, it may work on 64 different pixels at a time (for each of them the inputs are slightly different, and thus you get slightly different color at the end). Every SIMD-VU has room for 512 scalar registers and 256 vector registers. AMD has claimed that each GCN compute unit (CU) has 64 KiB Local Data Share (LDS). The CU scheduler

2331-484: A set of 83 patches to be merged into Linux kernel mainline 3.17 for supporting their Graphics Core Next-based Radeon graphics cards. The so-called HSA kernel driver resides in the directory /drivers/gpu/hsa , while the DRM graphics device drivers reside in /drivers/gpu/drm and augment the already existing DRM drivers for Radeon cards. This very first implementation focuses on a single "Kaveri" APU and works alongside

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2442-520: A simpler compiler . GCN graphics chips were fabricated with CMOS at 28 nm, and with FinFET at 14 nm (by Samsung Electronics and GlobalFoundries ) and 7 nm (by TSMC ), available on selected models in AMD's Radeon HD 7000 , HD 8000 , 200 , 300 , 400 , 500 and Vega series of graphics cards, including the separately released Radeon VII. GCN was also used in the graphics portion of Accelerated Processing Units (APUs), including those in

2553-554: A time. Some CPU architectures include multiple AGUs so more than one address-calculation operation can be executed simultaneously, which brings further performance improvements due to the superscalar nature of advanced CPU designs. For example, Intel incorporates multiple AGUs into its Sandy Bridge and Haswell microarchitectures , which increase bandwidth of the CPU memory subsystem by allowing multiple memory-access instructions to be executed in parallel. Many microprocessors (in smartphones and desktop, laptop, server computers) have

2664-446: A useful computer requires thousands or tens of thousands of switching devices. The overall speed of a system is dependent on the speed of the switches. Vacuum-tube computers such as EDVAC tended to average eight hours between failures, whereas relay computers—such as the slower but earlier Harvard Mark I —failed very rarely. In the end, tube-based CPUs became dominant because the significant speed advantages afforded generally outweighed

2775-439: A very small number of ICs; usually just one. The overall smaller CPU size, as a result of being implemented on a single die, means faster switching time because of physical factors like decreased gate parasitic capacitance . This has allowed synchronous microprocessors to have clock rates ranging from tens of megahertz to several gigahertz. Additionally, the ability to construct exceedingly small transistors on an IC has increased

2886-637: Is a means of identification where the official nomenclature is unknown or uncertain. The policy of recognition reporting names was continued into the Cold War for Soviet, other Warsaw Pact , and Communist Chinese aircraft. Although this was started by the Air Standards Co-ordinating Committee (ASCC) formed by the United States, United Kingdom, Canada, Australia, and New Zealand, it was extended throughout NATO as

2997-599: Is an open-source RTL implementation of the AMD Southern Islands GPGPU microarchitecture. In November 2015, AMD announced its Boltzmann Initiative, which aims to enable the porting of CUDA -based applications to a common C++ programming model. At the Super Computing 15 event, AMD displayed a Heterogeneous Compute Compiler (HCC), a headless Linux driver and HSA runtime infrastructure for cluster-class high-performance computing, and

3108-400: Is defined by the CPU's instruction set architecture (ISA). Often, one group of bits (that is, a "field") within the instruction, called the opcode, indicates which operation is to be performed, while the remaining fields usually provide supplemental information required for the operation, such as the operands. Those operands may be specified as a constant value (called an immediate value), or as

3219-494: Is generally referred to as the " classic RISC pipeline ", which is quite common among the simple CPUs used in many electronic devices (often called microcontrollers). It largely ignores the important role of CPU cache, and therefore the access stage of the pipeline. Some instructions manipulate the program counter rather than producing result data directly; such instructions are generally called "jumps" and facilitate program behavior like loops , conditional program execution (through

3330-483: Is greater or whether they are equal; one of these flags could then be used by a later jump instruction to determine program flow. Fetch involves retrieving an instruction (which is represented by a number or sequence of numbers) from program memory. The instruction's location (address) in program memory is determined by the program counter (PC; called the "instruction pointer" in Intel x86 microprocessors ), which stores

3441-791: Is known as Async Compute. For a given shader, the GPU drivers may also schedule instructions on the CPU to minimize latency. The geometry processor contains a Geometry Assembler, a Tesselator, and a Vertex Assembler. The Tesselator is capable of doing tessellation in hardware as defined by Direct3D 11 and OpenGL 4.5 (see AMD January 21, 2017), and succeeded ATI TruForm and hardware tessellation in TeraScale as AMD's then-latest semiconductor intellectual property core . One compute unit (CU) combines 64 shader processors with 4 texture mapping units (TMUs). The compute units are separate from, but feed into,

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3552-400: Is largely addressed in modern processors by caches and pipeline architectures (see below). The instruction that the CPU fetches from memory determines what the CPU will do. In the decode step, performed by binary decoder circuitry known as the instruction decoder , the instruction is converted into signals that control other parts of the CPU. The way in which the instruction is interpreted

3663-530: Is most often credited with the design of the stored-program computer because of his design of EDVAC, and the design became known as the von Neumann architecture , others before him, such as Konrad Zuse , had suggested and implemented similar ideas. The so-called Harvard architecture of the Harvard Mark I , which was completed before EDVAC, also used a stored-program design using punched paper tape rather than electronic memory. The key difference between

3774-737: Is the IBM PowerPC -based Xenon used in the Xbox 360 ; this reduces the power requirements of the Xbox 360. Another method of addressing some of the problems with a global clock signal is the removal of the clock signal altogether. While removing the global clock signal makes the design process considerably more complex in many ways, asynchronous (or clockless) designs carry marked advantages in power consumption and heat dissipation in comparison with similar synchronous designs. While somewhat uncommon, entire asynchronous CPUs have been built without using

3885-703: Is the hardware functional block, choosing which wavefronts the SIMD-VU executes. It picks one SIMD-VU per cycle for scheduling. This is not to be confused with other hardware or software schedulers. A shader is a small program written in GLSL that performs graphics processing, and a kernel is a small program written in OpenCL that performs GPGPU processing. These processes don't need that many registers, but they do need to load data from system or graphics memory. This operation comes with significant latency. AMD and Nvidia chose similar approaches to hide this unavoidable latency:

3996-447: Is to never have to report to anyone that their son "was killed in an operation called 'Bunnyhug' or 'Ballyhoo'." Presently, British forces tend to use one-word names, presumably in keeping with their post-World War II policy of reserving single words for operations and two-word names for exercises. British operation code names are usually randomly generated by a computer and rarely reveal its components or any political implications unlike

4107-488: The IBM z13 has a 96 KiB L1 instruction cache. Most CPUs are synchronous circuits , which means they employ a clock signal to pace their sequential operations. The clock signal is produced by an external oscillator circuit that generates a consistent number of pulses each second in the form of a periodic square wave . The frequency of the clock pulses determines the rate at which a CPU executes instructions and, consequently,

4218-546: The Manchester Mark 1 ran its first program during the night of 16–17 June 1949. Early CPUs were custom designs used as part of a larger and sometimes distinctive computer. However, this method of designing custom CPUs for a particular application has largely given way to the development of multi-purpose processors produced in large quantities. This standardization began in the era of discrete transistor mainframes and minicomputers , and has rapidly accelerated with

4329-698: The NATO reporting name for aircraft, rockets and missiles. These names were considered by the Soviets as being like a nickname given to one's unit by the opponents in a battle. The Soviets did not like the Sukhoi Su-25 getting the code name " Frogfoot ". However, some names were appropriate, such as "Condor" for the Antonov An-124 , or, most famously, "Fulcrum" for the Mikoyan MiG-29 , which had

4440-576: The PlayStation 4 and Xbox One . The GCN instruction set is owned by AMD and was developed specifically for GPUs. It has no micro-operation for division . Documentation is available for: An LLVM compiler back end is available for the GCN instruction set. It is used by Mesa 3D . GNU Compiler Collection 9 supports GCN 3 and GCN 5 since 2019 for single-threaded, stand-alone programs, with GCC 10 also offloading via OpenMP and OpenACC . MIAOW

4551-589: The Radeon R9 290X . Discrete GPUs (Sea Islands family): Code name During World War I , names common to the Allies referring to nations, cities, geographical features, military units, military operations, diplomatic meetings, places, and individual persons were agreed upon, adapting pre-war naming procedures in use by the governments concerned. In the British case names were administered and controlled by

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4662-512: The Rhine ) was deliberately named to suggest the opposite of its purpose – a defensive "watch" as opposed to a massive blitzkrieg operation, just as was Operation Weserübung ( Weser -exercise), which signified the plans to invade Norway and Denmark in April 1940. Britain and the United States developed the security policy of assigning code names intended to give no such clues to

4773-611: The USAAF , invented a system for the identification of Japanese military aircraft. Initially using short, " hillbilly " boys' names such as " Pete ", " Jake ", and " Rufe ", the system was later extended to include girls' names and names of trees and birds, and became widely used by the Allies throughout the Pacific theater of war. This type of naming scheme differs from the other use of code names in that it does not have to be kept secret, but

4884-673: The Unified Video Decoder , Video Coding Engine , and AMD TrueAudio . The Video Coding Engine is a video encoding ASIC , first introduced with the Radeon HD 7000 series . The initial version of the VCE added support for encoding I and P frames H.264 in the YUV420 pixel format, along with SVE temporal encode and Display Encode Mode, while the second version added B-frame support for YUV420 and YUV444 I-frames. VCE 3.0 formed

4995-474: The main memory . A cache is a smaller, faster memory, closer to a processor core , which stores copies of the data from frequently used main memory locations . Most CPUs have different independent caches, including instruction and data caches , where the data cache is usually organized as a hierarchy of more cache levels (L1, L2, L3, L4, etc.). All modern (fast) CPUs (with few specialized exceptions ) have multiple levels of CPU caches. The first CPUs that used

5106-656: The render output units (ROPs). Each compute unit consists of the following: Four Compute units are wired to share a 16KiB L1 instruction cache and a 32KiB L1 data cache, both of which are read-only. A SIMD-VU operates on 16 elements at a time (per cycle), while a SU can operate on one a time (one/cycle). In addition, the SU handles some other operations, such as branching. Every SIMD-VU has some private memory where it stores its registers. There are two types of registers: scalar registers (S0, S1, etc.), which hold 4 bytes number each, and vector registers (V0, V1, etc.), which each represent

5217-453: The AGU, various address-generation calculations can be offloaded from the rest of the CPU, and can often be executed quickly in a single CPU cycle. Capabilities of an AGU depend on a particular CPU and its architecture . Thus, some AGUs implement and expose more address-calculation operations, while some also include more advanced specialized instructions that can operate on multiple operands at

5328-431: The ALU's output word size), an arithmetic overflow flag will be set, influencing the next operation. Hardwired into a CPU's circuitry is a set of basic operations it can perform, called an instruction set . Such operations may involve, for example, adding or subtracting two numbers, comparing two numbers, or jumping to a different part of a program. Each instruction is represented by a unique combination of bits , known as

5439-626: The American names (e.g., the 2003 invasion of Iraq was called "Operation Telic" compared to Americans' "Operation Iraqi Freedom", obviously chosen for propaganda rather than secrecy). Americans prefer two-word names, whereas the Canadians and Australians use either. The French military currently prefer names drawn from nature (such as colors or the names of animals), for instance Opération Daguet ("brocket deer") or Opération Baliste ("Triggerfish"). The CIA uses alphabetical prefixes to designate

5550-468: The CPU can fetch the data from actual memory locations. Those address-generation calculations involve different integer arithmetic operations , such as addition, subtraction, modulo operations , or bit shifts . Often, calculating a memory address involves more than one general-purpose machine instruction, which do not necessarily decode and execute quickly. By incorporating an AGU into a CPU design, together with introducing specialized instructions that use

5661-479: The CPU to access main memory . By having address calculations handled by separate circuitry that operates in parallel with the rest of the CPU, the number of CPU cycles required for executing various machine instructions can be reduced, bringing performance improvements. While performing various operations, CPUs need to calculate memory addresses required for fetching data from the memory; for example, in-memory positions of array elements must be calculated before

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5772-422: The CPU to malfunction. Another major issue, as clock rates increase dramatically, is the amount of heat that is dissipated by the CPU . The constantly changing clock causes many components to switch regardless of whether they are being used at that time. In general, a component that is switching uses more energy than an element in a static state. Therefore, as clock rate increases, so does energy consumption, causing

5883-467: The CPU to require more heat dissipation in the form of CPU cooling solutions. One method of dealing with the switching of unneeded components is called clock gating , which involves turning off the clock signal to unneeded components (effectively disabling them). However, this is often regarded as difficult to implement and therefore does not see common usage outside of very low-power designs. One notable recent CPU design that uses extensive clock gating

5994-477: The Graphics Command Processor. Since the third iteration of GCN, the hardware contains two schedulers : one to schedule "wavefronts" during shader execution (the CU Scheduler, or Compute Unit Scheduler) and the other to schedule execution of draw and compute queues. The latter helps performance by executing compute operations when the compute units (CUs) are underutilized due to graphics commands limited by fixed function pipeline speed or bandwidth. This functionality

6105-559: The Inter Services Security Board (ISSB) staffed by the War Office . This procedure was coordinated with the United States when it entered the war . Random lists of names were issued to users in alphabetical blocks of ten words and were selected as required. Words became available for re-use after six months and unused allocations could be reassigned at discretion and according to need. Judicious selection from

6216-640: The Second World War, the British allocation practice favored one-word code names ( Jubilee , Frankton ). That of the Americans favored longer compound words, although the name Overlord was personally chosen by Winston Churchill himself. Many examples of both types can be cited, as can exceptions. Winston Churchill was particular about the quality of code names. He insisted that code words, especially for dangerous operations, would be not overly grand nor petty nor common. One emotional goal he mentions

6327-602: The US (just across the Bering Strait from Nome, Alaska). The names of colors are generally avoided in American practice to avoid confusion with meteorological reporting practices. Britain, in contrast, made deliberately non-meaningful use of them, through the system of rainbow codes . Although German and Italian aircraft were not given code names by their Allied opponents, in 1942, Captain Frank T. McCoy, an intelligence officer of

6438-509: The United States code names are commonly set entirely in upper case. This is not done in other countries, though for the UK in British documents the code name is in upper case while operation is shortened to OP e.g., "Op. TELIC". This presents an opportunity for a bit of public-relations ( Operation Just Cause ), or for controversy over the naming choice (Operation Infinite Justice, renamed Operation Enduring Freedom ). Computers are now used to aid in

6549-431: The advent and eventual success of the ubiquitous personal computer , the term CPU is now applied almost exclusively to microprocessors. Several CPUs (denoted cores ) can be combined in a single processing chip. Previous generations of CPUs were implemented as discrete components and numerous small integrated circuits (ICs) on one or more circuit boards. Microprocessors, on the other hand, are CPUs manufactured on

6660-428: The advent of the transistor . Transistorized CPUs during the 1950s and 1960s no longer had to be built out of bulky, unreliable, and fragile switching elements, like vacuum tubes and relays . With this improvement, more complex and reliable CPUs were built onto one or several printed circuit boards containing discrete (individual) components. In 1964, IBM introduced its IBM System/360 computer architecture that

6771-403: The available allocation could result in clever meanings and result in an aptronym or backronym , although policy was to select words that had no obviously deducible connection with what they were supposed to be concealing. Those for the major conference meetings had a partial naming sequence referring to devices or instruments which had a number as part of their meaning, e.g., the third meeting

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6882-564: The complexity and number of transistors in a single CPU many fold. This widely observed trend is described by Moore's law , which had proven to be a fairly accurate predictor of the growth of CPU (and other IC) complexity until 2016. While the complexity, size, construction and general form of CPUs have changed enormously since 1950, the basic design and function has not changed much at all. Almost all common CPUs today can be very accurately described as von Neumann stored-program machines. As Moore's law no longer holds, concerns have arisen about

6993-423: The complexity scale, a machine language program is a collection of machine language instructions that the CPU executes. The actual mathematical operation for each instruction is performed by a combinational logic circuit within the CPU's processor known as the arithmetic–logic unit or ALU. In general, a CPU executes an instruction by fetching it from memory, using its ALU to perform an operation, and then storing

7104-486: The control unit as part of the von Neumann architecture . In modern computer designs, the control unit is typically an internal part of the CPU with its overall role and operation unchanged since its introduction. The arithmetic logic unit (ALU) is a digital circuit within the processor that performs integer arithmetic and bitwise logic operations. The inputs to the ALU are the data words to be operated on (called operands ), status information from previous operations, and

7215-453: The desired operation. The action is then completed, typically in response to a clock pulse. Very often the results are written to an internal CPU register for quick access by subsequent instructions. In other cases results may be written to slower, but less expensive and higher capacity main memory . For example, if an instruction that performs addition is to be executed, registers containing operands (numbers to be summed) are activated, as are

7326-429: The drawbacks of globally synchronous CPUs. For example, a clock signal is subject to the delays of any other electrical signal. Higher clock rates in increasingly complex CPUs make it more difficult to keep the clock signal in phase (synchronized) throughout the entire unit. This has led many modern CPUs to require multiple identical clock signals to be provided to avoid delaying a single signal significantly enough to cause

7437-453: The early 1980s). In the 1960s, MOS ICs were slower and initially considered useful only in applications that required low power. Following the development of silicon-gate MOS technology by Federico Faggin at Fairchild Semiconductor in 1968, MOS ICs largely replaced bipolar TTL as the standard chip technology in the early 1970s. As the microelectronic technology advanced, an increasing number of transistors were placed on ICs, decreasing

7548-578: The era of specialized supercomputers like those made by Cray Inc and Fujitsu Ltd . During this period, a method of manufacturing many interconnected transistors in a compact space was developed. The integrated circuit (IC) allowed a large number of transistors to be manufactured on a single semiconductor -based die , or "chip". At first, only very basic non-specialized digital circuits such as NOR gates were miniaturized into ICs. CPUs based on these "building block" ICs are generally referred to as "small-scale integration" (SSI) devices. SSI ICs, such as

7659-503: The execution of an instruction, the entire process repeats, with the next instruction cycle normally fetching the next-in-sequence instruction because of the incremented value in the program counter . If a jump instruction was executed, the program counter will be modified to contain the address of the instruction that was jumped to and program execution continues normally. In more complex CPUs, multiple instructions can be fetched, decoded and executed simultaneously. This section describes what

7770-527: The existing Radeon kernel graphics driver (kgd). Hardware schedulers are used to perform scheduling and offload the assignment of compute queues to the ACEs from the driver to hardware, by buffering these queues until there is at least one empty queue in at least one ACE. This causes the HWS to immediately assign buffered queues to the ACEs until all queues are full or there are no more queues to safely assign. Part of

7881-401: The faster the clock, the more instructions the CPU will execute each second. To ensure proper operation of the CPU, the clock period is longer than the maximum time needed for all signals to propagate (move) through the CPU. In setting the clock period to a value well above the worst-case propagation delay , it is possible to design the entire CPU and the way it moves data around the "edges" of

7992-810: The fifth rocket seen at Tyura-Tam . When more information resulted in knowing a bit about what a missile was used for, it would be given a designation like "SS-6", for the sixth surface-to-surface missile design reported. Finally, when either an aircraft or a missile was able to be photographed with a hand-held camera, instead of a reconnaissance aircraft, it was given a name like " Flanker " or " Scud " – always an English word, as international pilots worldwide are required to learn English. The Soviet manufacturer or designation – which may be mistakenly inferred by NATO – has nothing to do with it. Jet-powered aircraft received two-syllable names like Foxbat , while propeller aircraft were designated with short names like Bull . Fighter names began with an "F", bombers with

8103-415: The fourth generation GCN microarchitecture, but were present in the third generation GCN microarchitecture for internal testing purposes. A driver update has enabled the hardware schedulers in third generation GCN parts for production use. This unit discards degenerate triangles before they enter the vertex shader and triangles that do not cover any fragments before they enter the fragment shader. This unit

8214-481: The grouping of multiple threads . AMD calls such a group a "wavefront", whereas Nvidia calls it a "warp". A group of threads is the most basic unit of scheduling of GPUs that implement this approach to hide latency. It is the minimum size of the data processed in SIMD fashion, the smallest executable unit of code, and the way to processes a single instruction over all of the threads in it at the same time. In all GCN GPUs,

8325-559: The individual transistors used by the PDP-8 and PDP-10 to SSI ICs, and their extremely popular PDP-11 line was originally built with SSI ICs, but was eventually implemented with LSI components once these became practical. Lee Boysel published influential articles, including a 1967 "manifesto", which described how to build the equivalent of a 32-bit mainframe computer from a relatively small number of large-scale integration circuits (LSI). The only way to build LSI chips, which are chips with

8436-439: The limits of integrated circuit transistor technology. Extreme miniaturization of electronic gates is causing the effects of phenomena like electromigration and subthreshold leakage to become much more significant. These newer concerns are among the many factors causing researchers to investigate new methods of computing such as the quantum computer , as well as to expand the use of parallelism and other methods that extend

8547-408: The location of a value that may be a processor register or a memory address, as determined by some addressing mode . In some CPU designs, the instruction decoder is implemented as a hardwired, unchangeable binary decoder circuit. In others, a microprogram is used to translate instructions into sets of CPU configuration signals that are applied sequentially over multiple clock pulses. In some cases

8658-406: The machine language opcode . While processing an instruction, the CPU decodes the opcode (via a binary decoder ) into control signals, which orchestrate the behavior of the CPU. A complete machine language instruction consists of an opcode and, in many cases, additional bits that specify arguments for the operation (for example, the numbers to be summed in the case of an addition operation). Going up

8769-421: The memory that stores the microprogram is rewritable, making it possible to change the way in which the CPU decodes instructions. After the fetch and decode steps, the execute step is performed. Depending on the CPU architecture, this may consist of a single action or a sequence of actions. During each action, control signals electrically enable or disable various parts of the CPU so they can perform all or part of

8880-540: 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). The form, design , and implementation of CPUs have changed over time, but their fundamental operation remains almost unchanged. Principal components of

8991-710: The number of individual ICs needed for a complete CPU. MSI and LSI ICs increased transistor counts to hundreds, and then thousands. By 1968, the number of ICs required to build a complete CPU had been reduced to 24 ICs of eight different types, with each IC containing roughly 1000 MOSFETs. In stark contrast with its SSI and MSI predecessors, the first LSI implementation of the PDP-11 contained a CPU composed of only four LSI integrated circuits. Since microprocessors were first introduced they have almost completely overtaken all other central processing unit implementation methods. The first commercially available microprocessor, made in 1971,

9102-449: The official name of the final product, a practice that was started in 2002 with Mac OS X v10.2 "Jaguar". Google and the AOSP also used this for their Android operating system until 2013, where the code name was different from the release name. Central processing unit A central processing unit ( CPU ), also called a central processor , main processor , or just processor , is

9213-583: The ones used in the Apollo Guidance Computer , usually contained up to a few dozen transistors. To build an entire CPU out of SSI ICs required thousands of individual chips, but still consumed much less space and power than earlier discrete transistor designs. IBM's System/370 , follow-on to the System/360, used SSI ICs rather than Solid Logic Technology discrete-transistor modules. DEC's PDP-8 /I and KI10 PDP-10 also switched from

9324-507: The part of the agency supporting an operation. In many cases with the United States, the first word of the name has to do with the intent of the program. Programs with "have" as the first word, such as Have Blue for the stealth fighter development, are developmental programs, not meant to produce a production aircraft. Programs that start with Senior, such as Senior Trend for the F-117, are for aircraft in testing meant to enter production. In

9435-409: The parts of the arithmetic logic unit (ALU) that perform addition. When the clock pulse occurs, the operands flow from the source registers into the ALU, and the sum appears at its output. On subsequent clock pulses, other components are enabled (and disabled) to move the output (the sum of the operation) to storage (e.g., a register or memory). If the resulting sum is too large (i.e., it is larger than

9546-544: The physical wiring of the computer. This overcame a severe limitation of ENIAC, which was the considerable time and effort required to reconfigure the computer to perform a new task. With von Neumann's design, the program that EDVAC ran could be changed simply by changing the contents of the memory. EDVAC was not the first stored-program computer; the Manchester Baby , which was a small-scale experimental stored-program computer, ran its first program on 21 June 1948 and

9657-501: The popularization of the integrated circuit (IC). The IC has allowed increasingly complex CPUs to be designed and manufactured to tolerances on the order of nanometers . Both the miniaturization and standardization of CPUs have increased the presence of digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in electronic devices ranging from automobiles to cellphones, and sometimes even in toys. While von Neumann

9768-473: The possible exception of the last level. Each extra level of cache tends to be bigger and is optimized differently. Other types of caches exist (that are not counted towards the "cache size" of the most important caches mentioned above), such as the translation lookaside buffer (TLB) that is part of the memory management unit (MMU) that most CPUs have. Caches are generally sized in powers of two: 2, 8, 16 etc. KiB or MiB (for larger non-L1) sizes, although

9879-451: The processor. It tells the computer's memory, arithmetic and logic unit and input and output devices how to respond to the instructions that have been sent to the processor. It directs the operation of the other units by providing timing and control signals. Most computer resources are managed by the CU. It directs the flow of data between the CPU and the other devices. John von Neumann included

9990-725: The relationship between number of SGPRs and VGPRs to the number of wavefronts, but essentially, for SGPRS it is between 104 and 512 per number of wavefronts, and for VGPRS it is 256 per number of wavefronts. Note that in conjunction with the SSE instructions , this concept of the most basic level of parallelism is often called a "vector width". The vector width is characterized by the total number of bits in it. Each SIMD Vector Unit has: Each SIMD-VU has 10 wavefront instruction buffers, and it takes 4 cycles to execute one wavefront. Many implementations of GCN are typically accompanied by several of AMD's other ASIC blocks. Including but not limited to

10101-478: The reliability problems. Most of these early synchronous CPUs ran at low clock rates compared to modern microelectronic designs. Clock signal frequencies ranging from 100 kHz to 4 MHz were very common at this time, limited largely by the speed of the switching devices they were built with. The design complexity of CPUs increased as various technologies facilitated the building of smaller and more reliable electronic devices. The first such improvement came with

10212-409: The result to memory. Besides the instructions for integer mathematics and logic operations, various other machine instructions exist, such as those for loading data from memory and storing it back, branching operations, and mathematical operations on floating-point numbers performed by the CPU's floating-point unit (FPU). The control unit (CU) is a component of the CPU that directs the operation of

10323-484: The rising and falling clock signal. This has the advantage of simplifying the CPU significantly, both from a design perspective and a component-count perspective. However, it also carries the disadvantage that the entire CPU must wait on its slowest elements, even though some portions of it are much faster. This limitation has largely been compensated for by various methods of increasing CPU parallelism (see below). However, architectural improvements alone do not solve all of

10434-543: The scheduling work performed includes prioritized queues which allow critical tasks to run at a higher priority than other tasks without requiring the lower priority tasks to be preempted to run the high priority task, therefore allowing the tasks to run concurrently with the high priority tasks scheduled to hog the GPU as much as possible while letting other tasks use the resources that the high priority tasks are not using. These are essentially Asynchronous Compute Engines that lack dispatch controllers. They were first introduced in

10545-452: The selection. And further, there is a distinction between the secret names during former wars and the published names of recent ones. A project code name is a code name (usually a single word, short phrase or acronym) which is given to a project being developed by industry , academia , government, and other concerns. Project code names are typically used for several reasons: Different organizations have different policies regarding

10656-540: The short switching time of a transistor in comparison to a tube or relay. The increased reliability and dramatically increased speed of the switching elements, which were almost exclusively transistors by this time; CPU clock rates in the tens of megahertz were easily obtained during this period. Additionally, while discrete transistor and IC CPUs were in heavy usage, new high-performance designs like single instruction, multiple data (SIMD) vector processors began to appear. These early experimental designs later gave rise to

10767-410: The simultaneous processing of two lower-precision numbers in place of a single higher-precision number. The Graphics Command Processor (GCP) is a functional unit of the GCN microarchitecture. Among other tasks, it is responsible for the handling of asynchronous shaders . The Asynchronous Compute Engine (ACE) is a distinct functional block serving computing purposes, whose purpose is similar to that of

10878-439: The term "CPU" is generally defined as a device for software (computer program) execution, the earliest devices that could rightly be called CPUs came with the advent of the stored-program computer . The idea of a stored-program computer had been already present in the design of John Presper Eckert and John William Mauchly 's ENIAC , but was initially omitted so that it could be finished sooner. On June 30, 1945, before ENIAC

10989-716: The uninitiated. For example, the British counter measures against the V-2 was called Operation Crossbow . The atomic bomb project centered in New Mexico was called the Manhattan Project , derived from the Manhattan Engineer District which managed the program. The code name for the American A-12 / SR-71 spy plane project, producing the fastest, highest-flying aircraft in the world,

11100-438: The use and publication of project code names. Some companies take great pains to never discuss or disclose project code names outside of the company (other than with outside entities who have a need to know, and typically are bound with a non-disclosure agreement ). Other companies never use them in official or formal communications, but widely disseminate project code names through informal channels (often in an attempt to create

11211-422: The use of a conditional jump), and existence of functions . In some processors, some other instructions change the state of bits in a "flags" register . These flags can be used to influence how a program behaves, since they often indicate the outcome of various operations. For example, in such processors a "compare" instruction evaluates two values and sets or clears bits in the flags register to indicate which one

11322-431: The usefulness of the classical von Neumann model. The fundamental operation of most CPUs, regardless of the physical form they take, is to execute a sequence of stored instructions that is called a program. The instructions to be executed are kept in some kind of computer memory . Nearly all CPUs follow the fetch, decode and execute steps in their operation, which are collectively known as the instruction cycle . After

11433-616: The von Neumann and Harvard architectures is that the latter separates the storage and treatment of CPU instructions and data, while the former uses the same memory space for both. Most modern CPUs are primarily von Neumann in design, but CPUs with the Harvard architecture are seen as well, especially in embedded applications; for instance, the Atmel AVR microcontrollers are Harvard-architecture processors. Relays and vacuum tubes (thermionic tubes) were commonly used as switching elements;

11544-612: Was Oxcart . The American group that planned that country's first ICBM was called the Teapot Committee . Although the word could stand for a menace to shipping (in this case, that of Japan), the American code name for the attack on the subtropical island of Okinawa in World War II was Operation Iceberg . The Soviet Union's project to base missiles in Cuba was named Operation Anadyr after their closest bomber base to

11655-555: Was "TRIDENT". Joseph Stalin , whose last name means "man of steel", was given the name "GLYPTIC", meaning "an image carved out of stone". Ewen Montagu , a British Naval intelligence officer, discloses in Beyond Top Secret Ultra that during World War II , Nazi Germany habitually used ad hoc code names as nicknames which often openly revealed or strongly hinted at their content or function. Some German code names: Conversely, Operation Wacht am Rhein (Watch on

11766-679: Was introduced with the Radeon HD 7790 and is also found in the Radeon HD 8770 , R7 260/260X, R9 290/290X, R9 295X2 , R7 360, and R9 390/390X , as well as Steamroller -based desktop "Kaveri" APUs and mobile "Kaveri" APUs and in the Puma -based "Beema" and "Mullins" APUs . It has multiple advantages over the original GCN, including FreeSync support, AMD TrueAudio and a revised version of AMD PowerTune technology. GCN 2nd generation introduced an entity called "Shader Engine" (SE). A Shader Engine comprises one geometry processor, up to 44 CUs (Hawaii chip), rasterizers, ROPs , and L1 cache. Not part of

11877-481: Was introduced with the fourth generation GCN microarchitecture. The GCN 1 microarchitecture was used in several Radeon HD 7000 series graphics cards. There are Asynchronous Compute Engines controlling computation and dispatching. ZeroCore Power is a long idle power saving technology, shutting off functional units of the GPU when not in use. AMD ZeroCore Power technology supplements AMD PowerTune . Discrete GPUs (Southern Islands family): The 2nd generation of GCN

11988-538: Was made, mathematician John von Neumann distributed a paper entitled First Draft of a Report on the EDVAC . It was the outline of a stored-program computer that would eventually be completed in August 1949. EDVAC was designed to perform a certain number of instructions (or operations) of various types. Significantly, the programs written for EDVAC were to be stored in high-speed computer memory rather than specified by

12099-647: Was so popular that it dominated the mainframe computer market for decades and left a legacy that is continued by similar modern computers like the IBM zSeries . In 1965, Digital Equipment Corporation (DEC) introduced another influential computer aimed at the scientific and research markets—the PDP-8 . Transistor-based computers had several distinct advantages over their predecessors. Aside from facilitating increased reliability and lower power consumption, transistors also allowed CPUs to operate at much higher speeds because of

12210-399: Was the Intel 4004 , and the first widely used microprocessor, made in 1974, was the Intel 8080 . Mainframe and minicomputer manufacturers of the time launched proprietary IC development programs to upgrade their older computer architectures , and eventually produced instruction set compatible microprocessors that were backward-compatible with their older hardware and software. Combined with

12321-429: Was used in a series of computers capable of running the same programs with different speeds and performances. This was significant at a time when most electronic computers were incompatible with one another, even those made by the same manufacturer. To facilitate this improvement, IBM used the concept of a microprogram (often called "microcode"), which still sees widespread use in modern CPUs. The System/360 architecture

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