What makes a fast CPU

CPU tuning: when the load is almost 100 percent ...

Friedrich Stiemer

Sometimes the processor works under full load even though you have no program open. We'll show you how to track down the reason for the high CPU load.

EnlargeIf the processor has to sweat too much: You can use the Task Manager to track down programs that are using the CPU to the full.

The computing power of a PC processor has increased exorbitantly since the invention of the semiconductor: The microprocessor Intel 8080 from 1974 managed 0.4 MIPS (million instructions per second), an Intel Core i5-6600K from 2015 comes to around 17,500 MIPS - over 40,000 times as much!

Apparently, the performance of the CPU is no longer as decisive for the PC speed as it used to be: SSDs and GPUs have overtaken the processor because they are better suited for multimedia and games. But the processor still plays an important role in the overall speed of a computer, and more often than you might think: surfing the web, formatting texts and tables, video streaming, multitasking with several programs and many other everyday tasks benefit significantly from a fast CPU.

If your PC gets stuck with these applications because of an older processor, you should still not upgrade immediately. A CPU upgrade is not only associated with costs for a new processor, but usually also for the motherboard, RAM and power supply - and with handicraft work anyway. It therefore makes more sense to relieve the CPU of tasks that other components can perform better and faster or that are less important for the performance of the PC. By exposing CPU brakes, you also increase your own comfort, because a CPU that is overloaded annoys with a loud fan and heats up the computer. We'll show you how to proceed so that your CPU is only concerned with what it should really be doing.

See also:Buying advice for the best CPU

Even simple programs use a lot of CPU power

EnlargeWith this example, Nvidia explains how GPU acceleration works in practice.

While a few years ago the CPU speed was the sole performance index for a computer, today it is more the combination of processor and graphics card speed. This works particularly well when calculating several tasks in parallel, which is why many programs use the GPU as an additional hardware accelerator for certain software functions and thus relieve the CPU at the same time. An expensive high-end processor alone is not enough to render complex games or detailed 3D models at high speed, for example. But even a strong graphics card cannot bring its full potential to the screen without a similarly powerful CPU - but in this case the difference is not noticeable too dramatically.

However, in order to let the graphics card handle general arithmetic tasks, the developers must first adapt the application accordingly. In addition, many normal everyday tasks cannot be parallelized or do not benefit from them. The exceptions are mostly multimedia tasks such as video and image processing. But if you only work with the Office programs, do research on the Internet or stream videos, then the CPU is still the service provider. However, you do not need an overly expensive model for the fields of application mentioned; in this case you can easily stay under 180 euros when buying a processor.

Multimedia and games: CPU and GPU have to go together

EnlargeOnly gamers and multimedia professionals usually need a powerful CPU. Those who only use Office or surf the Internet are well served with an entry-level model.

However, if you want to edit pictures or videos more often, or if you want to play graphically complex games, then both a fast processor and a powerful graphics card must be installed in the computer. The graphics card can show its strengths in these applications. Editing high-resolution video material, complex effects and running games get a decent boost in speed. However, you shouldn't neglect the CPU performance too much, because after all, the processor provides the GPU with the tasks to be calculated. And if the CPU is too weak, it can become a bottleneck and limit the performance of the graphics card. Nevertheless, it doesn't have to be the most expensive chip currently available. A good rule of thumb is that if you buy new components, the processor should cost about the same as your desired graphics card.

Hyperthreading & Co .: This speeds up the CPU

Up until a few years ago, the only way to achieve more CPU performance seemed to be through a higher clock frequency. But at some point this path leads to a dead end. Because if the CPU is too fast, delays can still occur: RAM or peripherals cannot provide the desired data in time, which is why the processor has to wait and the potential computing power does not even come into play. The solution to this bottleneck problem: The CPU processes several tasks at the same time instead of one after the other.

This parallelization comes into play in a processor on several levels: One level is called “pipeling” and can be seen as an assembly line for the execution of instructions. An instruction is divided into different phases: If an instruction changes from the first to the second phase, a new instruction immediately moves into phase 1. The more phases or pipelines a CPU has, the more instructions can be processed in parallel. The next step in parallelization is multithreading. Here the processor holds several tasks (threads) that it can process alternately. This allows thread 2 to be processed while thread 1 is waiting for data from memory. However, not all tasks can be parallelized, as it can happen that, for example, one thread has to wait for another. In order for the processor to process certain tasks at the same time, the software must also be programmed accordingly - this is complex and time-consuming.

Intel uses another technology called Simultaneous Multithreading (SMT) in its processors. It enables several threads to be processed in parallel. These program sequences are also processed independently of one another, which means that they can rarely get in each other's way. In this way, the computing power of the processor can be better divided, which leads to more efficient operation and, among other things, to lower power consumption.

With Hyperthreading (HAT) technology, an Intel CPU simulates additional processor cores for the operating system - a dual-core processor with HT then becomes a quad-core for Windows, for example. The aim is to use the functional units more effectively and to bridge storage waiting times. Hyperthreading is even more efficient if what is known as prefetching works well: This technology loads data and commands into memory in advance because it believes that they will be used next.

Relief for the CPU: How to expose performance hogs

However, if you do not even know whether you need a more powerful processor at all, then you should monitor the utilization of the chip. You can find out the current workload in real time with on-board tools such as the task manager or the Windows resource monitor. Call up the first-mentioned menu by right-clicking on "Task Manager", then click on the "Performance" tab and you will see the current, complete CPU load including the load for the last 60 seconds. You can access the resource monitor by pressing the key combination Windows + R and typing "resmon" in the run window and confirming with Return. All processor cores are listed in the "CPU" tab. In this way, you can also find out whether certain programs that you use frequently can even use multiple computing cores, i.e. master so-called multithreading.

EnlargeThe good old Task Manager also shows you the current utilization of the CPU.

In this way, system brakes can also be detected immediately: In the Task Manager, click on the “Processes” tab. Sort the entries according to CPU usage by clicking on the entry. You can now see in descending order which process is using the most processor power. It can even happen that you discover a piece of software that you are not familiar with. Because malware can also lodge itself in the system unnoticed and, for example, constantly send data to dubious dealers or crackers. You can often recognize such processes by their cryptic process names or by a process that is unknown to you. Of course, there may be times when you are not sure what the selected process is really about. For more details, right-click on the entry and select "Open file path" from the context menu. Windows will then guide you to the appropriate location for the associated program.

You can stop incriminating processes that you consider unnecessary by right-clicking on them and selecting "End task". Make sure that you do not deactivate your antivirus protection or other important programs that are necessary for proper operation! Now make sure that the CPU load has decreased. If this is the case, you can prevent these processes from being restarted the next time you switch on by throwing them out of the Windows autostart: Type “msconfig” in the run window, confirm your entry, and select the next one Window (“System configuration”) the register entry “System start”. All programs that start automatically with Windows are listed there. Remove the checkmarks from programs that are not used or are seldom used. Starting with Windows 10 you can also find the system start via the start menu. However, if your processor is still under high load after the cleanup, it is time for a new CPU - or new software.

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