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Bonnell (microarchitecture)
Bonnell is a CPU microarchitecture used by Intel Atom processors which can execute up to two instructions per cycle. Like many other x86 microprocessors, it translates x86 instructions ( CISC instructions) into simpler internal operations (sometimes referred to as micro-ops, effectively RISC style instructions) prior to execution. The majority of instructions produce one micro-op when translated, with around 4% of instructions used in typical programs producing multiple micro-ops. The number of instructions that produce more than one micro-op is significantly fewer than the P6 and NetBurst microarchitectures. In the Bonnell microarchitecture, internal micro-ops can contain both a memory load and a memory store in connection with an ALU operation, thus being more similar to the x86 level and more powerful than the micro-ops used in previous designs. This enables relatively good performance with only two integer ALUs, and without any instruction reordering, speculative execution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
45 Nanometer
Per the International Technology Roadmap for Semiconductors, the 45 nm process is a MOSFET technology node referring to the average half-pitch of a memory cell manufactured at around the 2007–2008 time frame. Matsushita and Intel started mass-producing 45 nm chips in late 2007, and AMD started production of 45 nm chips in late 2008, while IBM, Infineon, Samsung, and Chartered Semiconductor have already completed a common 45 nm process platform. At the end of 2008, SMIC was the first China-based semiconductor company to move to 45 nm, having licensed the bulk 45 nm process from IBM. In 2008, TSMC moved on to a 40nm process. Many critical feature sizes are smaller than the wavelength of light used for lithography (i.e., 193 nm and 248 nm). A variety of techniques, such as larger lenses, are used to make sub-wavelength features. Double patterning has also been introduced to assist in shrinking distances between features, especially if dry lit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetBurst (microarchitecture)
The NetBurst microarchitecture, called P68 inside Intel, was the successor to the P6 microarchitecture in the x86 family of central processing units (CPUs) made by Intel. The first CPU to use this architecture was the Willamette-core Pentium 4, released on November 20, 2000 and the first of the Pentium 4 CPUs; all subsequent Pentium 4 and Pentium D variants have also been based on NetBurst. In mid-2004, Intel released the ''Foster'' core, which was also based on NetBurst, thus switching the Xeon CPUs to the new architecture as well. Pentium 4-based Celeron CPUs also use the NetBurst architecture. NetBurst was replaced with the Core microarchitecture based on P6, released in July 2006. Technology The NetBurst microarchitecture includes features such as Hyper-threading, Hyper Pipelined Technology, Rapid Execution Engine, Execution Trace Cache, and replay system which all were introduced for the first time in this particular microarchitecture, and some never appeared again aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra-mobile PC
An ultra-mobile PC, or ultra-mobile personal computer (UMPC), is a miniature version of a pen computer, a class of laptop whose specifications were launched by Microsoft and Intel in spring 2006. Sony had already made a first attempt in this direction in 2004 with its Sony U-series, Vaio U series, which was only sold in Asia. UMPCs are generally smaller than subnotebooks, have a TFT display measuring (diagonally) about , are operated like Tablet computer, tablet PCs using a touchscreen or a stylus, and can also have a physical Computer keyboard, keyboard. There is no clear boundary between subnotebooks and ultra-mobile PCs, but UMPCs commonly have Major factors other than the common clamshell laptop design, such as having small keys on either side of the screen, or having a slide-out keyboard. The first-generation UMPCs were simple Personal computer, PCs running Linux or an adapted version of Microsoft's Tablet computer, tablet PC operating system. With the announcement of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Pipeline
In computer engineering, instruction pipelining or ILP is a technique for implementing instruction-level parallelism within a single processor. Pipelining attempts to keep every part of the processor busy with some instruction by dividing incoming instructions into a series of sequential steps (the eponymous "pipeline") performed by different processor units with different parts of instructions processed in parallel. Concept and motivation In a pipelined computer, instructions flow through the central processing unit (CPU) in stages. For example, it might have one stage for each step of the von Neumann cycle: Fetch the instruction, fetch the operands, do the instruction, write the results. A pipelined computer usually has "pipeline registers" after each stage. These store information from the instruction and calculations so that the logic gates of the next stage can do the next step. This arrangement lets the CPU complete an instruction on each clock cycle. It is common for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyper-Threading
Hyper-threading (officially called Hyper-Threading Technology or HT Technology and abbreviated as HTT or HT) is Intel's proprietary simultaneous multithreading (SMT) implementation used to improve parallelization of computations (doing multiple tasks at once) performed on x86 microprocessors. It was introduced on Xeon server processors in February 2002 and on Pentium 4 desktop processors in November 2002. Since then, Intel has included this technology in Itanium, Atom, and Core 'i' Series CPUs, among others. For each processor core that is physically present, the operating system addresses two virtual (logical) cores and shares the workload between them when possible. The main function of hyper-threading is to increase the number of independent instructions in the pipeline; it takes advantage of superscalar architecture, in which multiple instructions operate on separate data in parallel. With HTT, one physical core appears as two processors to the operating system, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Performance Per Watt
In computing, performance per watt is a measure of the energy efficiency of a particular computer architecture or computer hardware. Literally, it measures the rate of computation that can be delivered by a computer for every watt of power consumed. This rate is typically measured by performance on the LINPACK benchmark when trying to compare between computing systems: an example using this is the Green500 list of supercomputers. Performance per watt has been suggested to be a more sustainable measure of computing than Moore’s Law. System designers building parallel computers, such as Google's hardware, pick CPUs based on their performance per watt of power, because the cost of powering the CPU outweighs the cost of the CPU itself. Spaceflight computers have hard limits on the maximum power available and also have hard requirements on minimum real-time performance. A ratio of processing speed to required electrical power is more useful than raw processing speed. D. J. Shirley; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I486
The Intel 486, officially named i486 and also known as 80486, is a microprocessor. It is a higher-performance follow-up to the Intel 386. The i486 was introduced in 1989. It represents the fourth generation of binary compatible CPUs following the 8086 of 1978, the Intel 80286 of 1982, and 1985's i386. It was the first tightly- pipelined x86 design as well as the first x86 chip to include more than one million transistors. It offered a large on-chip cache and an integrated floating-point unit. A typical 50 MHz i486 executes around 40 million instructions per second (MIPS), reaching 50 MIPS peak performance. It is approximately twice as fast as the i386 or i286 per clock cycle. The i486's improved performance is thanks to its five-stage pipeline with all stages bound to a single cycle. The enhanced FPU unit on the chip was significantly faster than the i387 FPU per cycle. The intel 80387 FPU ("i387") was a separate, optional math coprocessor that was ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P5 (microarchitecture)
The Pentium (also referred to as P5, its microarchitecture, or i586) is a fifth generation, 32-bit x86 microprocessor that was introduced by Intel on March 22, 1993, as the very first CPU in the Pentium brand. It was instruction set compatible with the 80486 but was a new and very different microarchitecture design from previous iterations. The P5 Pentium was the first superscalar x86 microarchitecture and the world's first superscalar microprocessor to be in mass productionmeaning it generally executes at least 2 instructions per clock mainly because of a design-first dual integer pipeline design previously thought impossible to implement on a CISC microarchitecture. Additional features include a faster floating-point unit, wider data bus, separate code and data caches, and many other techniques and features to enhance performance and support security, encryption, and multiprocessing, for workstations and servers when compared to the next best previous industry standard proce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectre (security Vulnerability)
Spectre refers to one of the two original transient execution CPU vulnerabilities (the other being Meltdown), which involve microarchitectural timing side-channel attacks. These affect modern microprocessors that perform branch prediction and other forms of speculation. On most processors, the speculative execution resulting from a branch misprediction may leave observable side effects that may reveal private data to attackers. For example, if the pattern of memory accesses performed by such speculative execution depends on private data, the resulting state of the data cache constitutes a side channel through which an attacker may be able to extract information about the private data using a timing attack. Two Common Vulnerabilities and Exposures IDs related to Spectre, (bounds check bypass, Spectre-V1, Spectre 1.0) and (branch target injection, Spectre-V2), have been issued. JIT engines used for JavaScript were found to be vulnerable. A website can read data stored ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meltdown (security Vulnerability)
Meltdown is one of the two original transient execution CPU vulnerabilities (the other being Spectre). Meltdown affects Intel x86 microprocessors, IBM POWER processors, and some ARM-based microprocessors. It allows a rogue process to read all memory, even when it is not authorized to do so. Meltdown affects a wide range of systems. At the time of disclosure (2018), this included all devices running any but the most recent and patched versions of iOS, Linux, macOS, or Windows. Accordingly, many servers and cloud services were impacted, as well as a potential majority of smart devices and embedded devices using ARM-based processors (mobile devices, smart TVs, printers and others), including a wide range of networking equipment. A purely software workaround to Meltdown has been assessed as slowing computers between 5 and 30 percent in certain specialized workloads, although companies responsible for software correction of the exploit reported minimal impact from general benchmark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Register Renaming
In computer architecture, register renaming is a technique that abstracts logical registers from physical registers. Every logical register has a set of physical registers associated with it. When a machine language instruction refers to a particular logical register, the processor transposes this name to one specific physical register on the fly. The physical registers are opaque and cannot be referenced directly but only via the canonical names. This technique is used to eliminate false data dependencies arising from the reuse of registers by successive instructions that do not have any real data dependencies between them. The elimination of these false data dependencies reveals more instruction-level parallelism in an instruction stream, which can be exploited by various and complementary techniques such as superscalar and out-of-order execution for better performance. Problem approach In a register machine, programs are composed of instructions which operate on values. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speculative Execution
Speculative execution is an optimization technique where a computer system performs some task that may not be needed. Work is done before it is known whether it is actually needed, so as to prevent a delay that would have to be incurred by doing the work after it is known that it is needed. If it turns out the work was not needed after all, most changes made by the work are reverted and the results are ignored. The objective is to provide more concurrency if extra resources are available. This approach is employed in a variety of areas, including branch prediction in pipelined processors, value prediction for exploiting value locality, prefetching memory and files, and optimistic concurrency control in database systems.Lazy and Speculative Execution |
