The whole truth about multi core processors

multi-core processors

The first computer processors with multi core processors appeared on the consumer market in the middle of the 2000s, but many users still do not quite understand what multicore processors are, and how to understand their characteristics.


A simple explanation of the question “what is a processor”

A microprocessor is one of the main devices in a computer. This dry official name is often abbreviated to simply “processor”). The processor is a microcircuit comparable in size to a matchbox. If you like, the processor is like a motor in a car. The most important part, but not the only one. The car also has wheels, a body, and a turntable with headlights. But it is the processor (like the car’s motor) that determines the power of the “car”.

Many people call the processor the system unit – the “box”, inside which all the components of the PC are located, but this is fundamentally wrong. The system unit is a computer case along with all its components – a hard disk, RAM and many other details.

The size of the processor compared to a coin.
The size of the processor compared to a coin. There are processors and larger, there are much smaller.

The processor function is computing. Not so important which ones. The fact is that all the work of a computer is tied exclusively to arithmetic calculations. Addition, multiplication, subtraction and other algebra – all this is done by a chip called “processor”. And the results of such calculations are displayed on the screen in the form of a game, a Word file, or just a desktop.

The main part of the computer that deals with computing is what a processor is.

What is the processor core and multicore

From time immemorial processor “centuries” these microcircuits were single-core. The core is, in fact, the processor itself. It’s the main part. Processors also have other parts — say, “legs” —contacts, microscopic “wiring” —but just the unit that is responsible for computing is called the processor core. When the processors became very small, the engineers decided to combine several cores inside one processor “case”.

If you imagine the processor in the form of an apartment, then the core is a large room in such an apartment. A one-room apartment is one processor core (a large room-hall), a kitchen, a bathroom, a corridor … A two-room apartment is already like two processor cores along with other rooms. There are three, and four, and even 12-room apartments. Also in the case of processors: inside a single crystal – “apartment” there can be several cores – “rooms”.

Multicore is the division of one processor into several identical functional blocks. The number of blocks is the number of cores within one processor.

Varieties of multi core processors

There is a misconception: “the more cores a processor has, the better.” This is how marketers try to present the case, who are paid to create this kind of misconception. Their task is to sell cheap processors, moreover, more expensive and in huge quantities. But in fact, the number of cores is far from the main characteristic of processors.

Let’s get back to the analogy of processors and apartments. A two-room apartment is more expensive, more convenient and prestigious than a one-room apartment. But only if these apartments are in the same area, they are equipped equally, and their repairs are similar. There are weak quad-core (or even 6-core) processors that are significantly weaker than dual-core ones. But it’s hard to believe it: still, the magic of large numbers 4 or 6 against “some kind” of two. However, this is exactly what happens very, very often. It seems like the same four-room apartment, but in a dead state, without repair, in a completely remote area – and even at the price of a chic “two-room apartment” in the very center.

How many cores are inside a processor?

For personal computers and laptops, single-core processors have not really been available for several years, and meeting them on sale is a rarity. The number of cores starts with two. Four cores – as a rule, these are more expensive processors, but there is a return on them. There are also 6-core processors, incredibly expensive and much less useful in practical terms. Few tasks can increase performance on these monstrous crystals.

There was an experiment by AMD to create 3-core processors, but this is already in the past. It turned out pretty well, but their time has passed.

By the way, AMD also produces multi-core processors, but, as a rule, they are significantly weaker than competitors from Intel. True, their price is much lower. Just be aware that the 4 cores from AMD will almost always be noticeably weaker than the same 4 cores made by Intel.

Now you know that processors have 1, 2, 3, 4, 6, and 12 cores. Single-core and 12-core processors are a rarity. Three core processors are a thing of the past. Six-core processors are either very expensive (Intel) or not so powerful (AMD) to overpay for a number. 2 and 4 cores are the most common and practical devices, from the weakest to very powerful.

The frequency of multi core processors

One of the characteristics of computer processors is their frequency. Those same megahertz (and more often – gigahertz). Frequency is an important characteristic, but far from the only one. Yes, perhaps not the most important one. For example, a dual-core processor with a frequency of 2 gigahertz is a more powerful offer than its single-core counterpart with a frequency of 3 gigahertz.

It is completely wrong to assume that the frequency of the processor is equal to the frequency of its cores times the number of cores. If it is simpler, then in a 2-core processor with a core frequency of 2 GHz, the total frequency is by no means equal to 4 GHz! Even the concept of “total frequency” does not exist. In this case, the processor frequency is exactly 2 GHz. No multiplications, additions or other operations.

And again, we’ll turn processors into apartments. If the ceiling height in each room is 3 meters, then the total height of the apartment will remain the same – all the same three meters, and not a centimeter higher. No matter how many rooms there are in such an apartment, the height of these rooms does not change. So is the clock frequency of the processor cores. It does not add up or multiply.

Virtual Multicore, or Hyper-Threading

There are also virtual processor cores. Hyper-Threading technology in Intel processors makes the computer “think” that there are actually 4 cores inside the dual-core processor. It is very similar to how a single hard drive is divided into several logical drives – local drives C, D, E and so on.

Hyper-Threading is a very useful technology in a number of tasks. Sometimes it happens that the processor core is only half used, and the rest of the transistors in its composition are idle. Engineers came up with a way to make these “loafers” work by dividing each physical processor core into two “virtual” parts. As if a sufficiently large room were divided by a partition into two.

Does such a trick with virtual cores make practical sense? Most often, yes, although it all depends on specific tasks. It seems that there are more rooms (and most importantly – they are used more rationally), but the area of ​​the room has not changed. In offices, such partitions are incredibly useful, in some residential apartments, too. In other cases, there is no sense at all in blocking the room (dividing the processor core into two virtual ones).

Note that the most expensive and productive processors of the Core i7 class are necessarily equipped with Hyper-Threading. They have 4 physical cores and 8 virtual ones. It turns out that 8 computational threads work simultaneously on the same processor. Less expensive, but also powerful IntelCore i5 processors consist of four cores, but Hyper-Threading does not work there. It turns out that Core i5 work with 4 threads of computing.

The ProcessorsCore i3 – typical “middling”, both in price and performance. They have two cores and no hint of Hyper-Threading. So it turns out that Core i3has only two processing threads. The same applies to the openly budget crystalsPentium and Celeron. Two cores, “hyper-trading” is missing = two threads.

Does a computer need a lot of cores? How many cores do you need in a processor?

All modern processors are powerful enough for common tasks. Internet browsing, correspondence in social networks and email, Word-PowerPoint-Excel office tasks: weak Atom, budget Celeron and Pentium are suitable for this work, not to mention more powerful Core i3. Two cores for normal operation are more than enough. A processor with a large number of cores will not bring a significant increase in speed.

For games, you should pay attention to the Core i3 or i5 processors. Rather, the performance in games will depend not on the processor, but on the video card. It’s rare in which game the full power of the Core i7 is required. Therefore, it is believed that games require no more than four processor cores, and more often two cores will do.

For serious work like special engineering programs, video coding and other resource-intensive tasks ,a really productive technique is required. Often, not only physical but also virtual processor cores are involved here. The more computing threads, the better. And no matter how much such a processor costs: for professionals, the price is not so important.

Is there any benefit from multi-core processors?

Of course, yes. At the same time, the computer is engaged in several tasks – at least the operation of Windows (by the way, these are hundreds of different tasks) and, at the same time, playing the movie. Playing music and browsing the internet. The work of a text editor and music included. Two processor cores – and these, in fact, two processors – will cope with different tasks faster than one. Two cores will make it a little faster. Four is even faster than two.

In the early years of the existence of multicore technology, not all programs were able to work even with two processor cores. By 2014, the vast majority of applications are well aware and able to take advantage of several cores. The speed of processing tasks on a dual-core processor rarely doubles, but there is almost always a performance gain.

Therefore, the deep-rooted myth that, supposedly, programs cannot use multiple cores is outdated information. Once it really was so, today the situation has improved dramatically. The benefits of multiple cores are undeniable, it is a fact.

When the processor has fewer cores – better

You should not buy a processor using the wrong formula “the more cores – the better.” This is not true. Firstly, 4, 6 and 8-core processors are significantly more expensive than their dual-core counterparts. A significant increase in price is far from always justified in terms of performance. For example, if an 8-core is only 10% faster than a CPU with fewer cores, but will be 2 times more expensive, then such a purchase is difficult to justify.

Secondly, the more cores the processor has, the more voracious it is in terms of power consumption. There is no point in buying a much more expensive laptop with a 4-core (8-thread) Core i7 if only text files are processed on this laptop, the Internet is browsed, and so on. There will be no difference with the dual-core (4 threads) Core i5, and the classic Core i3 with only two computing threads will not yield to the more eminent “colleague”. And with a battery, such a powerful laptop will work much less than the economical and undemanding Core i3.

Multi core processors in mobile phones and tablets

A fashion for multiple cores within a single processor also applies to mobile devices. Smartphones, along with tablets with a large number of cores, almost never use all the capabilities of their microprocessors. Dual-core mobile computers sometimes really work a little faster, but 4, and even more so 8 cores, are outright overkill. The battery is consumed completely godlessly, and powerful computing devices are simply idle idle. Conclusion – multi-core processors in phones, smartphones and tablets are just a tribute to marketing, not an urgent need. Computers are more demanding devices than phones. They really need two processor cores. Four – do not hurt. 6 and 8 are overkill in ordinary tasks and even in games.

A brief summary of the article

  • The core of the processor is its component. In fact, a standalone processor inside the case. Dual-core processor – two processors inside one.
  • Multi-core is comparable to the number of rooms inside the apartment. Two-room apartments are better than one-room apartments, but only with other things being equal (location of the apartment, condition, area, ceiling height).
  • The assertion that the more cores a processor has, the better it is – a marketing ploy, is a completely wrong rule. After all, an apartment is chosen far not only by the number of rooms but also by its location, repair, and other parameters. The same applies to several cores inside the processor.
  • There is a “virtual” multi core technology Hyper-Threading. Thanks to this technology, each “physical” core is divided into two “virtual” ones. It turns out that a 2-core processor with Hyper-Threading has only two real cores, but these processors simultaneously process 4 computing threads. This is a really useful feature, but a 4-threaded processor cannot be considered a four-core one.
  • For Intel desktop processors: Celeron – 2 cores and 2 threads. Pentium – 2 cores, 2 threads. Core i3 – 2 cores, 4 threads. Core i5 – 4 cores, 4 threads. Core i7 – 4 cores, 8 threads. Notebook (mobile) Intel CPUs have a different number of cores/threads.
  • For mobile computers, energy efficiency (in practice, battery life) is often more important than the number of cores.

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