The computer's central processing unit has a number of technical characteristics, which determine the most main characteristic of any processor - its performance and the meaning of each of them is useful to know. Why? In order to be well versed in reviews and testing, as well as CPU markings in the future.In this article I will try to reveal basic specifications processor in a presentation that is understandable for beginners.
Main technical characteristics central processor:
- Clock frequency;
- Bit depth;
- Cache memory;
- Number of Cores;
- Frequency and bit depth system bus;
Let's take a closer look at these characteristics
Clock frequency
Clock frequency -an indicator of the speed at which commands are executed by the central processor.
Tact is the period of time required to perform an elementary operation.
In the recent past, the clock speed of a central processor was identified directly with its performance, that is, the higher the clock speed of the CPU, the more productive it is. In practice we have a situation whereprocessors with different frequencies have the same performance because they can execute a different number of instructions in one clock cycle (depending on the core design, bus bandwidth, cache memory).
The processor clock speed is proportional to the system bus frequency ( see below).
Bit depth
Processor capacity is a value that determines the amount of information that the central processor is capable of processing in one clock cycle.
For example, if the processor is 16-bit, this means that it is capable of processing 16 bits of information in one clock cycle.
I think everyone understands that the higher the processor bit depth, the larger volumes of information it can process.
Typically, the higher the processor capacity, the higher its performance.
Currently, 32- and 64-bit processors are used. The size of the processor does not mean that it is obliged to execute commands with the same bit size.
Cache memory
First of all, let's answer the question, what is cache memory?
Cache memory is a high-speed computer memory designed for temporary storage of information (code of executable programs and data) needed by the central processor.
What data is stored in cache memory?
Most frequently used.
What is the purpose of cache memory?
The point is that performance random access memory, compared to CPU performance is much lower. It turns out that the processor is waiting for data to arrive from RAM - which reduces the performance of the processor, and therefore the performance of the entire system. Cache memory reduces processor latency by storing data and code of executable programs that were accessed most frequently by the processor (the difference between cache memory and computer RAM is that the speed of cache memory is tens of times higher).
Cache memory, like regular memory, has a capacity. The higher the cache memory capacity, the larger volumes of data it can work with.
There are three levels of cache memory: cache memory first (L1), second (L2) and third (L3). Most often in modern computers The first two levels apply.
Let's take a closer look at all three levels of cache memory.
First cache level is the fastest and most expensive memory.
Level 1 cache is located on the same chip as the processor and operates at CPU frequency (hence the fastest performance) and used directly by the processor core.
The capacity of the first level cache is small (due to its high cost) and is measured in kilobytes (usually no more than 128 KB).
L2 cache is a high-speed memory that performs the same functions as the L1 cache. The difference between L1 and L2 is that the latter has lower speed but larger capacity (from 128 KB to 12 MB), which is very useful for performing resource-intensive tasks.
L3 cache located on the motherboard. L3 is significantly slower than L1 and L2, but faster than RAM. It is clear that the volume of L3 is greater than the volume of L1 and L2. Level 3 cache is found in very powerful computers.
Number of Cores
Modern processor manufacturing technologies make it possible to place more than one core in one package. The presence of several cores significantly increases the performance of the processor, but this does not mean that the presence n cores gives increased performance in n once. In addition, the problem with multi-core processors is thatand today there are relatively few programs written taking into account the presence of multiple processor cores.
The main characteristics of the bus are its capacity and operating frequency. Bus frequency is the clock frequency at which data is exchanged between the processor and the computer's system bus.
Naturally, the higher the bit depth and frequency of the system bus, the higher the processor performance.
The high data transfer speed of the bus allows the processor and computer devices to quickly receive the necessary information and commands.
The operating frequency of all modern processors is several times higher than the system bus frequency, so the processor works as much as the system bus allows it. The amount by which the processor frequency exceeds the system bus frequency is called a multiplier.
Some of the most important performance parameters of the hardware installed in your computer are determined by how many times per second information is sent and received from a particular device (processor, memory, disk drives, etc.). These parameters are measured in megahertz and are called “frequency”. When they talk about the frequency of the maternal boards, and not the processors and memory chips installed on it, they usually mean frequency data buses.
Instructions
Use the proprietary software to determine the bus frequency on the motherboard. software- it often contains information and configuration utilities that allow you to find out, among other settings, the parameter you need. Look for such a utility on the optical disk in the motherboard's packaging box. boards. If you do not have a disk, then its contents can be downloaded from the manufacturer’s website. For example, for maternal boards ASRock Fatal1ty P67 is called F-Stream Tuning, and frequency tires boards can be seen on its Hardware Monitor tab, next to the inscription BCLC/PCI-E Frequency. On the Overclocking tab you can not only see it, but also change it using the slider next to the same inscription.
Install, as an alternative to proprietary software, a universal program for determining the parameters and monitoring the equipment installed on the computer. Such applications are distributed by companies that are not related to the production of motherboards, and therefore are designed to work with devices from many manufacturers. For example, it may be very popular free utility CPU-Z (http://cpuid.com/softwares/cpu-z.html) or at least popular program, providing information on a wider range peripheral devices, AIDA (http://aida64.com). If you install the last of them, then to find out information about the operating frequency of the system bus, expand the “Motherboard” section in the menu, click the line with exactly the same name and look at the number indicated opposite the inscription “Real frequency” in the “Bus properties” section FSB".
Go to the BIOS control panel if there is no way to find out frequency mother bus boards directly from operating system. In the basic I/O system, it is also not always possible to see the value of this parameter - often a specific value is not specified here, but the Auto parameter is set. However, you can try this option - look among the settings for the one that mentions FSB Freqency or CPU Freqency. The exact name depends on the BIOS version used, and it will most likely be located on the Advanced tab.
Instructions
To determine the bus frequency you need to use special programs. One of the pretty simple utilities CPUID CPU-Z is also completely free. Download it from the Internet and install it on your computer. Launch the program.
Once launched, select the CPU tab. In the window that appears, you can see basic information about your processor. In the lower left part of the window there is a Clocks section. In this section you need to find the Bus Speed line. The value in this line is the bus operating frequency.
Another program that can be used to find out the bus frequency is called AIDA64 Extreme Edition. Unlike CPUID CPU-Z, this program will be able to show the current bus frequency and the permissible limits for its increase. The application is paid, but there is a free period of one month. Download the program from the Internet, install it on your computer and run. AIDA64 Extreme Edition will begin scanning the system. Once completed, you will be taken to the main menu.
In the right window of the main menu there will be a list of devices. From this list, select "System Board". In the next window also select "System Board". A window will appear with information about your motherboard configuration. The information will be divided into several sections. Find the section “FSB bus properties”, in it there is the line “Real frequency”. The value in this line will be the bus frequency.
You can also use the AI Booster program to determine the frequency. Install it, restart your computer, after which the program will start automatically, since it is built into autorun. In the application menu, click on the Display tuning panel icon. This will open an additional panel. Next, select Tuning. Just below this item you can see the bus frequency.
To fully optimize the operation of your computer, it is recommended to change the operating parameters of the central processor and RAM. Naturally, before starting this process, it is better to check the stability of these devices.
You will need
- - CPU-Z;
- - Speed Fan.
Instructions
Install the CPU-Z program and run it. Find out the current processor performance. The overall CPU operating frequency is obtained by multiplying the multiplier by the bus frequency. To ensure maximum effect from overclocking the processor, it is necessary to increase the bus frequency.
Restart your computer and open BIOS menu. To do this, press the Delete key when the PC starts booting. Press F1 and Ctrl buttons simultaneously to open the menu additional settings. Some motherboard models may require different key combinations.
Open the menu responsible for setting the parameters of the RAM and CPU. Increase the CPU bus frequency. Raise the voltage supplied to the processor by changing the value of the CPU Voltage item. Press the F10 button to save the settings and restart your computer.
Use the CPU-Z utility to assess the stability of the processor. Open Control Panel and select the System and Security menu. Go to "Administration". Click on the “Check” shortcut Windows memory" Diagnose your RAM status by restarting your computer. If the system does not detect any failures, then enter the BIOS menu again.
FSB - many users have probably heard about this more than once computer term. This name is given to one of the most important components of the motherboard - the system bus.
As you know, the heart of anyone personal computer is the central processing unit. But it's not just the processor that determines a PC's architecture. It also largely depends on the set of auxiliary chips (chipset) used on the motherboard. In addition, the processor cannot function without internal buses, which are a set of signal conductors on the motherboard. The functions of buses include transferring information between various devices computer and central processor. The characteristics of internal buses, in particular, their bandwidth and frequency, largely determine the characteristics of the computer itself.
Perhaps the most important bus on which computer performance most depends is the FSB bus. The abbreviation FSB stands for Front Side Bus, which can be translated as “front” tire. The main functions of the bus include data transfer between the processor and the chipset. More precisely, the FSB is located between the processor and the “northbridge” chip of the motherboard, where the RAM controller is located.
Communication between the north bridge and another important chip in the chipset, called the “south bridge” and containing I/O device controllers, in modern computers is usually carried out using another bus, which is called Direct Media Interface.
Typically, the processor and bus have the same base frequency, which is called the reference or real. In the case of a processor, its final frequency is determined by the product of the reference frequency and a certain multiplier. Generally speaking, the real FSB frequency is usually the main frequency of the motherboard, which is used to determine the operating frequencies of all other devices.
In most old computers, the actual frequency of the system bus also determined the frequency of the RAM, but now memory can often have a different frequency - if the memory controller is located in the processor itself. In addition, it should be borne in mind that the actual bus frequency is not equivalent to its effective frequency, which is determined by the number of bits of information transmitted per second.
Currently, this bus is considered obsolete and is gradually being replaced by newer ones - QuickPath and HyperTransport. The QuickPath system bus is developed by Intel, and HyperTransport is developed by AMD.
Front Side Bus in Traditional Chipset Architecture
QuickPath
The QuickPath Interconnect (QPI) was developed by Intel in 2008 to replace the traditional FSB. QPI was originally used in computers based on Xeon processors and Itanium. The development of QPI was intended to challenge what had already been used for some time in AMD chipsets Hypertransport bus.
Although QPI is usually called a bus, its properties nevertheless differ significantly from the properties of a traditional system bus, and in its design it is a wired connection of the interconnect type. QPI is an integral part of a technology that Intel calls QuickPath architecture. In total, QPI has 20 data lines, and the total number of QPI bus wires is 84. Like Hypertransport, QuickPath technology implies that the memory controller is built into the central processor itself, so it is used only to communicate with the I/O controller. The QuickPath bus can operate at frequencies of 2.4, 2.93, 3.2, 4.0 or 4.8 GHz.
QuickPath Interconnect Layout
Hypertransport
The Hypertransport bus is developed by AMD. Hypertransport has performance characteristics similar to the QuickPath bus, but it was created several years earlier than the QuickPath bus. The bus is distinguished by its original architecture and topology, completely different from the architecture and topology of the FSB. The Hypertransport bus is based on such components as tunnels, bridges, links and chains. The bus architecture is designed to eliminate bottlenecks in the connection diagram between individual devices on the motherboard and transmit information at high speeds and with few delays.
There are several versions of Hypertransport, operating at different clock frequencies - from 200 MHz to 3.2 GHz. The maximum bus throughput for version 3.1 is over 51 GB/s (both directions). The bus is used both to replace the FSB bus in single-processor systems and as the main bus in multiprocessor computers.
Hypertransport bus layout
Direct Media Interface
A few words should be said about such a type of system bus as Direct Media Interface (DMI). DMI is designed to connect between the two main chipset chips - the north and south bridges. The DMI bus was first used in Intel chipsets in 2004.
The DMI bus has architectural properties that combine it with a peripheral bus such as PCI Express. Specifically, DMI uses serial data lines and also has separate wires for transmitting and receiving data.
Place of DMI (indicated in red) in computer architecture.
The original DMI implementation provided data transfer up to 10 Gbit/s in each direction. The modern version of the bus, DMI 2.0, can support speeds of 20 GB/s in both directions. Many mobile versions DMIs have half the number of signal lines compared to desktop DMI versions.
Conclusion
The system bus is a kind of blood “artery” of any computer, ensuring the transfer of data from the “heart” of the motherboard - the processor - to the rest of the motherboard microcircuits and, above all, to the north bridge, which controls the operation of the RAM. Currently, in various motherboard architectures you can find both the traditional FSB bus and highly efficient Hypertransport and QPI buses with complex topologies. The characteristics, performance, and architecture of the system bus are important factors that determine the potential capabilities of a computer.
X86 processors (CPUs) are designed to interface with motherboards that have a fixed front side bus (FSB) frequency, which for example can be 133 MHz in most computers. The system bus frequency is one of two factors that determine the operating frequency of the central processor. Given this connection, it is technically possible to increase the system bus speed to increase CPU speed, but this is a risky endeavor and can lead to negative effects, such as motherboard failure.
FSB and multiplier
The central processor usually has a built-in frequency multiplier or multiplier, which, along with the system bus frequency, affects the final operating frequency. For example, modern processor Intel Core i7-860 has a 21X multiplier and is designed to work in motherboards with FSB 133 MHz, which when mutually multiplied gives a resulting processor frequency of 2.8 GHz. The processor frequency, which is usually written on the protective metal cover of the processor or on its packaging, is in fact not a rigid value and can be changed by increasing the system bus frequency or changing the coefficient (multiplier).
Overclocking (overclocking)
Augmentation process clock frequency pushing the system bus to higher values supported by the processor is called overclocking or overclocking. For example, increasing the system bus frequency from 133 MHz to 150 MHz will lead to an increase in the frequency Intel processor Core i7-860 to 3.15 GHz (multiply 150 MHz by 21 and you get this figure, which needs to be converted to gigahertz). Overclocking the processor allows you to increase system performance, which is needed to run applications that require processor resources. Overclocking also helps save you money - thanks to it, you can buy a lower-frequency processor with good overclocking potential, increase the FSB frequency and achieve from this processor the performance characteristic of more expensive and high-frequency processors (from the same line).
Risk of overclocking
Most components of a personal computer use the system bus frequency to operate synchronously with each other. Therefore, do not forget that by overclocking the processor and increasing this frequency, you also increase it for other system components, including the processor cache memory. This can lead to their operating modes going beyond normal limits and disrupting the operation of the system as a whole. The effect of overclocking is difficult to predict - it can lead to excessive heat generation and conflicts in the operation of the CPU and other components. Moreover, the computer may completely fail or, conversely, you simply will not be able to overclock the computer due to limitations set by the manufacturer.
If you are lucky, the computer may continue to operate normally, but will become much faster. You should note that overclocking system components will automatically void the manufacturer's warranty. Typically, hand-built computers assembled by enthusiasts or small companies from specially selected components are subject to overclocking. Large companies like Dell and HP protect their products from such risky operations.
Frequency reduction
Separately, it is worth mentioning that the reverse process is possible - a decrease in the system bus frequency. This results in reduced system performance and reduced heat generation from its components. This course of action is taken when problems arise with system cooling. For example, if the computer ends up in an aggressive environment or in a closed, unventilated room. In addition, frequency reduction can be used to reduce power consumption in cases where high performance from the processor is not required.
Multiplier lock
As we have already figured out, changing the FSB system bus frequency leads to a change in the operating frequencies of all system components, but changing the multiplication factor is safer, since it only affects the processor itself. Therefore, overclocking by increasing the multiplier has a much greater chance of success. But, to the great regret of overclocking enthusiasts, most processors (especially Intel) have a locked multiplier that cannot be changed. Only some premium processor models have an unlocked multiplier and they are designed specifically for overclocking enthusiasts.