What Is a Performance Index?

The strength of the computer function or the performance is not determined by a certain index, but by a combination of its system structure, instruction system, hardware composition, software configuration and other factors.

Computing speed is an important indicator of computer performance. Generally speaking, computer operation speed (average operation speed) refers to what can be performed per second

A group of computers processed at the same time

Internal memory, also referred to as

External memory capacity usually refers to

Host I / O speed, depends on

Memory performance is determined by two factors, one is

Rotational Speed, yes

The main frequency of the CPU is the clock frequency of the CPU core (CPU Clock Speed). Generally speaking how many megahertz of a certain CPU is, and this number of megahertz is "the main frequency of the CPU". Many people think that the CPU's clock speed is its operating speed, but it is not. The main frequency of the CPU indicates the speed of the digital pulse signal oscillation in the CPU, which has no direct relationship with the actual computing capacity of the CPU. Since the main frequency does not directly represent the operation speed, in some cases, it is likely that the actual operation speed of the CPU with a higher frequency will be lower. In electronic technology, a pulse signal is an analog signal that is continuously emitted at a certain voltage amplitude and a certain time interval. The time interval between pulse signals is called the period; and the number of pulses generated in a unit time (such as 1 second) is called the frequency. Frequency is a measurement name describing the number of pulses that a cyclic signal (including a pulse signal) appears in a unit time; the standard measurement unit for frequency is Hz (hertz). The system clock in a computer is a typical pulse signal generator with a fairly accurate and stable frequency. Frequency is represented by "f" in mathematical expressions, and its corresponding units are: Hz (hertz), kHz (kilohertz), MHz (megahertz), GHz (GHz). Among them, 1GHz = 1000MHz, 1MHz = 1000kHz, and 1kHz = 1000Hz. Calculate the time unit of the pulse signal period and the corresponding conversion relationship: s (seconds), ms (milliseconds), s (microseconds), ns (nanoseconds). The highest in 4.2G history: 1s = 1000ms, 1ms = 1000s, 1s = 1000ns. The main frequency of the CPU is the clock frequency of the CPU core (CPU Clock Speed). Generally speaking how many megahertz of a certain CPU is, and this number of megahertz is "the main frequency of the CPU". There is a certain relationship between the main frequency and the actual operation speed, but there is no established formula that can quantify the numerical relationship between the two, because the operation speed of the CPU depends on the performance indicators (cache, instruction set, The number of CPU bits, etc.). Since the main frequency does not directly represent the operation speed, in some cases, it is likely that the actual operation speed of the CPU with a higher frequency will be lower. For example, AMD's AthlonFX series CPUs can mostly use lower clock speeds to reach the higher CPU frequency performance of Intel's Pentium 4 series CPUs. Therefore, AthlonFX series CPUs are named after PR values. Therefore, the main frequency is only one aspect of the performance of the CPU, and does not represent the overall performance of the CPU.

The clock speed of the CPU does not represent the speed of the CPU, but increasing the clock speed is crucial to increase the speed of the CPU. For example, suppose a certain CPU executes an arithmetic instruction in one clock cycle. When the CPU runs at 100MHz, it will be twice as fast as when it runs at 50MHz. Because the 100MHz clock cycle takes 50% less time than the 50MHz clock cycle, that is, a CPU operating at 100MHz takes only 10ns to execute an operation instruction, which is only half as long as 20ns when operating at 50MHz. It's twice as fast. It's just that the overall operating speed of the computer depends not only on the CPU operation speed, but also on the operation of other sub-systems. Only when the main frequency is increased, the operating speed of each sub-system and the data transmission speed between each sub-system After it is improved, the overall operating speed of the computer can be really improved.
Increasing the CPU operating frequency is mainly limited by the production process. Because the CPU is manufactured on a semiconductor silicon chip, wires need to be connected between the components on the silicon chip. As the wires are required to be thinner and shorter as possible at high frequencies, this can reduce stray interference such as distributed capacitance of the wires. To ensure that the CPU operation is correct. Therefore, the limitation of manufacturing process is one of the biggest obstacles to the development of CPU clock frequency. The more mainstream memory frequencies are 667MHz and 800MHz DDR2 memory, and 1333MHz DDR3 memory. More high-end calculations are based on GHz. For example, the main frequency required by high-end enterprises is 2.4GHz.
The main frequency of the processor has two concepts that are closely related to it: frequency multiplication and external frequency. The external frequency is the CPU's reference frequency, and the unit is also MHz. FSB is the speed of synchronous operation between CPU and motherboard, and in most computer systems, FSB is also the speed of synchronous operation between memory and motherboard. In this way, it can be understood that the CPU's FSB is directly connected to the memory. To achieve the synchronous running state between the two; frequency multiplication is a multiple of the ratio of the main frequency to the external frequency. Main frequency, external frequency, multiplier, the relationship: main frequency = external frequency × multiplier. Earlier CPUs did not have the concept of "multiplier". At that time, the speed of the main frequency and the system bus were the same. With the development of technology, the speed of the CPU is getting faster and faster, and accessories such as memory and hard disks can no longer keep up with the speed of the CPU. The emergence of frequency multiplication has solved this problem, and it can keep components such as memory still working at relatively low speeds. Under the system bus frequency, the CPU's main frequency can be infinitely increased by multiplication (in theory). We can think of the FSB as a production line in the machine, and the multiplier is the number of production lines. The speed of a machine (the main frequency) is naturally the speed of the production line (the external frequency) multiplied by the number of production lines. (Octave). Manufacturers have basically locked up the multiplier. To overclock, only start with the external frequency. Through the combination of the frequency multiplier and the external frequency, set the jumper on the motherboard or set the soft overclock in the BIOS to achieve a partial improvement of the overall computer performance. ^2] .