Overclocking for everyone. "Home" overclocking processor with an open multiplier

It so happened that for nearly twenty years of IT practice, I have never had to deal with overclocking - others somehow all had interests. Nevertheless, choosing the configuration for the next new (although now far from new) computer, for some reason I settled on the Intel processor with an open multiplier - i5-2500K. Why did I do this, now I don’t remember, maybe I was planning to figure out what old overclocking is after all, in my old age. And one evening, when there was nothing to do, I realized that the moment had come, and went deeper into the study of the issue, and the next evening I applied what I learned in practice. About what I am going to report.

Overclocking theory

Acceleration issues have interested mankind all the time since the moment when computer technology came to the masses. The main driver of overclocking is the spirit of competition, excitement, the desire to achieve better results than others. Well, its main object is innocent processors that are subjected to inhuman loads in order to obtain these very results.There are two main ways to overclock the processor. The first is an increase in the frequency of the BCLK clock, which through the factors determines the frequency of the processor, memory, buses and bridges. This option is universal in principle, but it has many nuances and limitations associated with a particular processor and motherboard, so that your experiments do not lead to the death of the computer, you need to carefully understand everything. The second way is to change the processor multiplier, the same one by which BCLK is multiplied, to get the operating frequency. This way is much safer (only the operating mode of the processor, and not the entire system, is subject to change) and simpler (essentially one parameter is responsible for overclocking), but there is one thing: the multiplier must be unlocked (allowed for change) by the processor manufacturer.
Initially, Intel processors had an open multiplier, but in the 90s of the last century, after a series of scandals related to re-marking processors by unscrupulous suppliers, when slow processors were accelerated and sold at the price of faster ones, the company blocked the multiplier. Since then, the unlocked multiplier was found only in top models "for enthusiasts", which, of course, were not cheap. The situation fundamentally changed with the advent of the second-generation Intel Core (Sandy Bridge) processors - in their lineup there were models with an unlocked multiplier for the mass consumer, which received the K index. Initially, the cost of K and non-K variants of one processor differed quite significantly, but now it has practically disappeared to no (e.g.



So, Intel itself has opened the way for "home", fast and highly qualified overclocking. It’s a sin not to take this opportunity, and I began my experiments. As a test bench, as I have already said, my long-suffering home computer acted again, by the way, it was completely unprepared for overclocking, rather, on the contrary, it was chosen for reasons of economy and noiselessness.

Experiment

According to the specification, the i5-2500K works on factors from 16 to 56. With standard parameters and using SpeedStep, we have 16x idle and 34x under load. Now start the process. "Home" overclocking has become so homely that it can now be made directly from Windows without entering the BIOS. But nevertheless, we will stay with oldfags for a start - only BIOS, only hardcore! However, a special hardcore will not work - there we will need only one parameter; in the BIOS of my motherboard ASUS P8Z68-V LX it is called CPU Ratio and is located in the menu CPU Power Management. To overclock the processor above standard values, you will also need to enable the Turbo Mode option (it does not apply to Intel Turbo Boost, which, on the contrary, is recommended to be turned off).
The first overclocking was tiny, up to 36x, in order to mark my entry into the ranks of overclockers. However, fanfare did not follow, and nothing happened at all, except for the frequency in the CPU monitor. The temperature also remained unchanged. The next level is 40x, a significant figure, until recently such a result (during overclocking "on the bus") was considered a grandmaster. The height was taken without the slightest effort and without changing the voltage on the processor. But the temperature, unfortunately, crawled up and at 100% load reached 68 degrees. There is nothing to be done, the cooling system installed on the computer proved to be completely unsuitable for overclocking.



Step Three 44x, i.e. 1 GHz gain. Making the face brick, I started the computer. “Well, no, that's enough,” he answered and flew out into the blue screen. It is necessary to increase the voltage of the processor. I immediately raised to 1.4 V, so that was enough. Now I decided to act through the GUI on Windows. In the AI ​​Suite software supplied with the ASUS motherboard, the Turbo V EVO component is responsible for overclocking. For its work, this program uses the TPU controller (TurboV Processing Unit) on the motherboard. The TPU module is so intelligent that it can, without human intervention, accelerate the system to the maximum possible parameters. Thus, the acceleration technology, from the point of view of the "teapot", has reached its highest point, when to get the result it is enough to press one button "do it so that everything gets hurt".
I was not able to really test the 4.4 GHz mode, since within a few seconds after starting the full load the temperature had risen to the maximum permissible, and I was forced to interrupt the experiment. However, I have no doubt that with normal cooling the processor would be stable - numerous experiments by other users convince me of this. Speaking specifically about the i5-2500K, then up to 4.5 GHz processors work for absolutely everyone, the 5 GHz result is pretty common, and the most stubborn ones have reached 5.2 GHz. I emphasize that we are talking about stable operation under a large (test or real) load. Thus, we are dealing with more than 50% increase in frequency with minimal material and mental costs.

Results and Conclusions

As expected, the results of computational tests crawled linearly upward with increasing frequency. For example, I chose the integer "chess" CPU Queen test. As you can see, with maximum overclocking, our processor “pushed” not only the extreme i7 of the first generation, but also the server Xeon (although initially inferior to both).



Someone is probably wondering what happened to the Windows Performance Index? Almost nothing, it increased by only one tenth, from 7.5 to 7.6. However, do not forget that for Windows 7 the maximum index value is 7.9, so a big jump could not happen.



Now let's try to answer the question, who needs this overclocking - except, directly, overclockers? However, they answered him before us: first of all, to fans of computer games. Experiments have shown that the processor power at standard frequencies is not enough to “power” top-end video cards, especially if there are several of them, and with increasing frequency to a certain limit, gaming performance also grows. Saturation occurs, by the way, at our "home" 4-4.5 GHz, it is at this frequency that the processor ceases to be the "bottleneck" of the entire system. In addition, people dealing with heavy media content, and, of course, dear fans of distributed computing, will definitely be happy with the extra gigahertz. I note