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Megahertz Myth
The megahertz myth, or in more recent cases the gigahertz myth, refers to the misconception of only using clock rate (for example measured in megahertz or gigahertz) to compare the performance of different microprocessors. While clock rates are a valid way of comparing the performance of different speeds of the same model and type of processor, other factors such as an amount of execution units, pipeline depth, cache hierarchy, branch prediction, and instruction sets can greatly affect the performance when considering different processors. For example, one processor may take two clock cycles to add two numbers and another clock cycle to multiply by a third number, whereas another processor may do the same calculation in two clock cycles. Comparisons between different types of processors are difficult because performance varies depending on the type of task. A benchmark is a more thorough way of measuring and comparing computer performance. The myth started around 1984 when compa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock Rate
Clock rate or clock speed in computing typically refers to the frequency at which the clock generator of a processor can generate pulses used to synchronize the operations of its components. It is used as an indicator of the processor's speed. Clock rate is measured in the SI unit of frequency hertz (Hz). The clock rate of the first generation of computers was measured in hertz or kilohertz (kHz), the first personal computers from the 1970s through the 1980s had clock rates measured in megahertz (MHz). In the 21st century the speed of modern CPUs is commonly advertised in gigahertz (GHz). This metric is most useful when comparing processors within the same family, holding constant other features that may affect performance. Determining factors Binning Manufacturers of modern processors typically charge higher prices for processors that operate at higher clock rates, a practice called binning. For a given CPU, the clock rates are determined at the end of the manufact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Processing Unit
A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary Processor (computing), processor in a given computer. Its electronic circuitry executes Instruction (computing), 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, CPU design, design, and implementation of CPUs have changed over time, but their fundamental operation remains almost unchanged. Principal components of a CPU include the arithmetic–logic unit (ALU) that performs arithmetic operation, arithmetic and Bitwise operation, logic operations, processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that orchestrates the #Fetch, fetching (from memory), #Decode, decoding and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stevenote
Stevenote is a colloquial term for keynote speeches given by Steve Jobs, former CEO of Apple, at events such as the Apple Worldwide Developers Conference, Macworld Expo, and Apple Expo. Because most Apple product releases were first shown to the public at these keynotes, "Stevenotes" caused substantial swings in Apple's stock price. The final Stevenote was delivered on June 6, 2011, when iCloud (Apple's cloud computing service) was announced. OS X Lion and iOS 5 were also announced on the same day. It was one of Jobs' last public appearances before his resignation as CEO on August 24 and his death on October 5 of that year. History In late 1996, Apple purchased NeXT, and Jobs returned to Apple after an 11-year hiatus following his forced resignation from the company in 1985. In mid-1997, he delivered a keynote address, with a detailed report on the company's status, featuring a satellite appearance by Microsoft CEO Bill Gates. Jobs announced a partnership with Microsoft with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steve Jobs
Steven Paul Jobs (February 24, 1955 – October 5, 2011) was an American businessman, inventor, and investor best known for co-founding the technology company Apple Inc. Jobs was also the founder of NeXT and chairman and majority shareholder of Pixar. He was a pioneer of the personal computer revolution of the 1970s and 1980s, along with his early business partner and fellow Apple co-founder Steve Wozniak. Jobs was born in San Francisco in 1955 and adopted shortly afterwards. He attended Reed College in 1972 before withdrawing that same year. In 1974, he traveled through India, Hippie trail, seeking enlightenment before later studying Buddhism in the West#Emerging mainstream western Buddhism, Zen Buddhism. He and Wozniak co-founded Apple in 1976 to further develop and sell Wozniak's Apple I personal computer. Together, the duo gained fame and wealth a year later with production and sale of the Apple II, one of the first highly successful mass-produced microcomputers. Jobs saw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macworld Expo
Macworld/iWorld (originally Macworld) was an information technology trade show with conference tracks dedicated to Apple's Mac platform. It was held annually in the United States during January. Originally ''Macworld Expo'' and then ''Macworld Conference & Exposition'', the gathering dates back to 1985. The conference was organized by International Data Group (IDG), co-publisher of ''Macworld'' magazine. On December 18, 2008, Apple announced that the 2009 Macworld Conference & Expo would be the last in which the company participates. On October 14, 2014, IDG suspended Macworld/iWorld indefinitely. History The first Macworld Expo occurred in 1985 in San Francisco. The conference itself was created by Peggy Kilburn, who helped to increase the size and profit of the event during her tenure (1985–1999). Among the speakers recruited by Kilburn were David Pogue, Steve Case, Bob LeVitus, as well as representatives from BMUG, LaserBoard, and other major user groups. Participation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Guardian
''The Guardian'' is a British daily newspaper. It was founded in Manchester in 1821 as ''The Manchester Guardian'' and changed its name in 1959, followed by a move to London. Along with its sister paper, ''The Guardian Weekly'', ''The Guardian'' is part of the Guardian Media Group, owned by the Scott Trust Limited. The trust was created in 1936 to "secure the financial and editorial independence of ''The Guardian'' in perpetuity and to safeguard the journalistic freedom and liberal values of ''The Guardian'' free from commercial or political interference". The trust was converted into a limited company in 2008, with a constitution written so as to maintain for ''The Guardian'' the same protections as were built into the structure of the Scott Trust by its creators. Profits are reinvested in its journalism rather than distributed to owners or shareholders. It is considered a newspaper of record in the UK. The editor-in-chief Katharine Viner succeeded Alan Rusbridger in 2015. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentium (original)
The Pentium (also referred to as the i586 or P5 Pentium) is a microprocessor introduced by Intel on March 22, 1993. It is the first CPU using the Pentium, Pentium brand. Considered the fifth generation in the x86 (8086) compatible line of processors, succeeding the i486, its implementation and microarchitecture was internally called ''P5''. Like the Intel i486, the Pentium is instruction set compatible with the 32-bit i386. It uses a very similar microarchitecture to the i486, but was extended enough to implement a dual integer instruction pipelining, pipeline design, as well as a more advanced floating-point unit (FPU) that was noted to be ten times faster than its predecessor. The Pentium was succeeded by the Pentium Pro in November 1995. In October 1996, the Pentium MMX was introduced, complementing the same basic microarchitecture of the original Pentium with the MMX (instruction set), MMX instruction set, larger caches, and some other enhancements. Intel discontinued the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I486
The Intel 486, officially named i486 and also known as 80486, is a microprocessor introduced in 1989. It is a higher-performance follow-up to the i386, Intel 386. It represents the fourth generation of binary compatible CPUs following the Intel 8086, 8086 of 1978, the Intel 80286 of 1982, and 1985's i386. It was the first tightly-instruction pipeline, pipelined x86 design as well as the first x86 chip to include more than one million transistors. It offered a large on-chip Cache (computing), cache and an integrated floating-point unit. When it was announced, the initial performance was originally published between 15 and 20 VAX Unit of Performance, VAX MIPS, between 37,000 and 49,000 Dhrystone, dhrystones per second, and between 6.1 and 8.2 double-precision Whetstone (benchmark), megawhetstones per second for both 25 and 33 MHz version. A typical 50 MHz i486 executes 41 million instructions per second Dhrystone MIPS and SPECint, SPEC integer rating of 27.9.Chen, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mac (computer)
Mac is a brand of personal computers designed and marketed by Apple Inc., Apple since 1984. The name is short for Macintosh (its official name until 1999), a reference to the McIntosh (apple), McIntosh apple. The current product lineup includes the MacBook Air and MacBook Pro laptops, and the iMac, Mac Mini, Mac Studio, and Mac Pro desktops. Macs are currently sold with Apple's UNIX-based macOS operating system, which is Proprietary software, not licensed to other manufacturers and exclusively Pre-installed software, bundled with Mac computers. This operating system replaced Apple's original Macintosh operating system, which has variously been named System, Mac OS, and Classic Mac OS. Jef Raskin conceived the Macintosh project in 1979, which was usurped and redefined by Apple co-founder Steve Jobs in 1981. The original Macintosh 128K, Macintosh was launched in January 1984, after Apple's 1984 (advertisement), "1984" advertisement during Super Bowl XVIII. A series of increment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apple Inc
Apple Inc. is an American multinational corporation and technology company headquartered in Cupertino, California, in Silicon Valley. It is best known for its consumer electronics, software, and services. Founded in 1976 as Apple Computer Company by Steve Jobs, Steve Wozniak and Ronald Wayne, the company was incorporated by Jobs and Wozniak as Apple Computer, Inc. the following year. It was renamed Apple Inc. in 2007 as the company had expanded its focus from computers to consumer electronics. Apple is the largest technology company by revenue, with billion in the 2024 fiscal year. The company was founded to produce and market Wozniak's Apple I personal computer. Its second computer, the Apple II, became a best seller as one of the first mass-produced microcomputers. Apple introduced the Lisa in 1983 and the Macintosh in 1984, as some of the first computers to use a graphical user interface and a mouse. By 1985, internal company problems led to Jobs leavin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PowerPC
PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., Apple–IBM–Motorola alliance, known as AIM alliance, AIM. PowerPC, as an evolving instruction set, has been named Power ISA since 2006, while the old name lives on as a trademark for some implementations of Power Architecture–based processors. Originally intended for personal computers, the architecture is well known for being used by Apple's desktop and laptop lines from 1994 until 2006, and in several videogame consoles including Microsoft's Xbox 360, Sony's PlayStation 3, and Nintendo's GameCube, Wii, and Wii U. PowerPC was also used for the Curiosity (rover), Curiosity and Perseverance (rover), Perseverance rovers on Mars and a variety of satellites. It has since become a niche architecture for personal computers, particularly with A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reduced Instruction Set Computer
In electronics and computer science, a reduced instruction set computer (RISC) is a computer architecture designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a complex instruction set computer (CISC), a RISC computer might require more instructions (more code) in order to accomplish a task because the individual instructions perform simpler operations. The goal is to offset the need to process more instructions by increasing the speed of each instruction, in particular by implementing an instruction pipeline, which may be simpler to achieve given simpler instructions. The key operational concept of the RISC computer is that each instruction performs only one function (e.g. copy a value from memory to a register). The RISC computer usually has many (16 or 32) high-speed, general-purpose registers with a load–store architecture in which the code for the register-register instructions (for performin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
