clock rate

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clock rate

[′kläk ‚rāt]
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Clock Rate


the change in clock correction per unit time. Different types of clock rates, such as diurnal and hourly, are distinguished, depending on the unit of time selected. With a negative clock rate, the clock runs fast; with a positive rate, it falls progressively behind true time. The magnitude of the clock rate depends on the adjustment of the clock but is not a reflection of the clock’s quality. It is affected by various factors related to the design of the clock mechanism and to external conditions of its operation. Therefore, whenever the precise time is required, as for example in astronomy, several clocks are used, and their rates are carefully studied by daily comparisons of their readings.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

clock rate

(processor, benchmark)
The fundamental rate in cycles per second at which a computer performs its most basic operations such as adding two numbers or transfering a value from one register to another.

The clock rate of a computer is normally determined by the frequency of a crystal. The original IBM PC, circa 1981, had a clock rate of 4.77 MHz (almost five million cycles/second). As of 1995, Intel's Pentium chip runs at 100 MHz (100 million cycles/second). The clock rate of a computer is only useful for providing comparisons between computer chips in the same processor family. An IBM PC with an Intel 486 CPU running at 50 MHz will be about twice as fast as one with the same CPU, memory and display running at 25 MHz. However, there are many other factors to consider when comparing different computers. Clock rate should not be used when comparing different computers or different processor families. Rather, some benchmark should be used. Clock rate can be very misleading, since the amount of work different computer chips can do in one cycle varies. For example, RISC CPUs tend to have simpler instructions than CISC CPUs (but higher clock rates) and pipelined processors execute more than one instruction per cycle.
This article is provided by FOLDOC - Free Online Dictionary of Computing (

clock speed

The internal heartbeat of a computer, also known as "clock rate." The clock circuit uses fixed vibrations generated from a quartz crystal to deliver a steady stream of pulses to the CPU. See clock and MHz.
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
The serial peripheral interface is a simple synchronous interface that uses hardware addressing and operates at clock rate of up to 50 megahertz (MHz).
AMD's APUs like the Ryzen 5 2400G are heavily bandwidth-limited, which means increasing your DDR4 clock rate can have a substantial impact on overall performance.
i) Clock distribution and clock skew problem reduces this allow wave pipelined circuits works at higher clock rate
In contrast, I3C offers a 12.5-MHz clock rate. SPI can handle the higher speeds, but it's a four-wire interface that lacks features like in-band addressing and peer-to-peer communications.
As shown in Figure 2, our compilation flow takes an application diagram as well as high-level design requirements, such as clock rate and throughput, and produces an optimized implementation with resource and timing estimates.
In 1984, Apple Computer began selling its first Macintosh model, which boasted a built-in 9-inch monochrome display, a clock rate of 8 megahertz and 128k of RAM.
The Cortex-M3 is a next generation core that offers better performance than the ARM7 at the same clock rate and other system enhancements such as modernized debug features and a higher level of support block integration.
Typically, that sampling happens faster than the target system clock rate, ideally four times to even 10 times the system clock rate.
The other approach is to use a DMA that runs at a higher clock rate than the RISC.
(1) 1.7 GHz: Maximum clock rate. Clock rate will change depending on usage conditions.
Referring to Figure 1, an eight-stage inverter chain has been simulated with 50 MHz input rate and 100 MHz power clock rate, and it has significant amount of delay at each stage which causes completely incorrect output logics at the seventh and eighth-stage.