Any technique has the ability to become obsolete and computer is not an exception. A PC, bought 5-7 years ago, was excellent at that time, and sometimes it doesn’t cope with modern tasks and there  arises the question of improving its performance.  Here you can choose from 2 options – buy a new system unit or upgrade the old one. Very often buying a new system unit is simply impossible – expensive licensed programs are installed on the existing one or there are no extra funds. In this case, we can follow the path of modernization.
Very old specimens, in the likeness 478, 775, AM2 sockets will not be considered because of their irrelevance and let’s start the review with a 1156 socket.
With 1156 socket, assembled on a h55 chipset all motherboard worked for DDR3 memory(up to the arrival of DDR4). DDR3 until now successfully copes with the tasks assigned to it, the question is only in volume. As a rule each slot of DDR3 chipsets H55, H61 supports up to 8 gigabytes of memory, which means that having 2 slots on the motherboard, you can increase the volume to 16 gigabytes. This volume will be enough for the normal operation of all applications in the next 2-3 years. It costs 1 bar 8GB DDR3 1600Mhz around 50 dollars, and the total cost of 16 gigabytes of memory will be only $ 100.
Next, let’s look at what processors we can put to get maximum performance in different sockets.

Socket 1156

Here we have the best option is the Core i7-870, which has 4 physical and 4 logical cores operating at a frequency of 2.93 Ghz and 3.6 Ghz in turbo mode. It costs about $ 75. It will perfectly cope with office tasks, but in modern games it will be already heavy. You will be able to play comfortably only on average settings.

Socket 1155

It should be said immediately, if you have a 3rd generation Core i5 processor, you will not feel much performance gain from any upgrade. For any other processor, we advise you to pay attention to the Core i7 3770K. It will cost you 150-180 dollars. On Board 4 physical, 4 logical cores with a clock frequency of 3.5 Ghz and 3.9 Ghz in turbo mode. The letter » K «means that the CPU multiplier is unlocked and can be»overclocked». This is a powerful processor despite the fact that it is not new. You will be able to run all modern games on high settings and the processor will cope with any office applications.

Socket 1150

Here we have an excellent example of engineering – Core i7 4770K. It’s a very good processor. With features very reminiscent of the 3770K, it represents the next generation of processor architecture with the code name Haswell. In the most popular Chinese online store, with free shipping, the processor costs around $ 220. The performance is an average of 15% less than the Core i5 8600K, which is very good and in the case of proper overclocking you will achieve the latter. Easily run any office and engineering programs, high-ultra game settings.

Socket AM3+

Owners of the platform from AMD recommend to look at the processor AMD FX8350, and, if you can not find it, to AMD FX 8320. AMD FX 8350 has 4 physical and 4 logical cores operating at frequencies up to 4Ghz. The price for the processor depending on the place of purchase will be 80-110 dollars.
Copes with any office applications. In the games we set high settings, in some games of 2018 something will have to be reduced to the average.

We will not consider more modern platforms. It is written a lot about them in different sources.

Graphics settings in games we take on the basis of the operation of the processor in conjunction with the AMD Radeon RX 580 8gb or 6gb Nvidia GTX 1060.

It can also improve the performance of the SSD drive installation, the transfer of the operating system and the most demanding programs.

If you decide to build a new computer, we recommend you to look at the AMD Ryzen 2700x processor on the AM4 socket. This 8-core, 16-stream processor in our opinion has the best price and performance and will give an excellent result, both in games and programs.