High CPU usage: What does this mean?

The CPU (Central Pro­cess­ing Unit) is the brain of a computer and performs many of its main tasks. It processes data and delegates commands. The speed at which all programs and processes run depends on the CPU’s per­for­mance capacity. The higher the per­for­mance of a CPU, the faster the PC will run. Depending on the ap­pli­ca­tions you open, CPU may increase. CPU speed changes are then no­tice­able in the time required for the system to start-up or the time it takes for ap­pli­ca­tions to respond to commands. When working with CPU-intensive programs (e.g. graphics and video editing software), you may notice that certain commands and actions may take longer to be executed.

That means slow pro­cess­ing per­for­mance may not be a sign that there’s an issue with the CPU itself. Instead, there may be too many CPU-intensive programs actively running at the same time and the CPU could have reached its usage limit. Thus, it’s important to examine CPU usage and causes for high usage before pre­ma­ture­ly deciding to replace a PC for a high-per­for­mance model.

By examining your CPU usage, you can check how in­ten­sive­ly running programs are being processed. The re­spec­tive value indicates what per­cent­age of a processor core’s total working time is actually being utilized to process data. CPU usage can amount to a maximum of 100 per cent. In other words, CPU usage can be an indicator of how much stress the processor is currently un­der­go­ing, and, if necessary, what capacity is still available.

To calculate this, the general operating time is compared to the actual per­for­mance duration. If CPU usage is too high, users will ex­pe­ri­ence long load and save times, and in the worst-case scenario, programs will start to freeze because the processor is over­loaded with too many pro­cess­ing commands.

At the same time, you can reach con­clu­sions about pro­cess­ing speed by checking the CPU tem­per­a­ture. With greater pro­cess­ing usage, more heat is produced by the processor core. Should the tem­per­a­ture increase beyond a threshold defined as the maximum limit by the man­u­fac­tur­er, computing per­for­mance will be curbed au­to­mat­i­cal­ly and the pro­cess­ing power will gradually decrease.

If you are a Linux user, you can display CPU usage with the “top” command. After entering it, you’ll obtain a list of all actively running processes and their CPU values and memory usage. The list is con­tin­u­ous­ly updated and is, for this reason, an optimal tool for mon­i­tor­ing system ac­tiv­i­ties. If you require more powerful al­ter­na­tives, you can download htop and Glances. They must be installed sep­a­rate­ly, but do provide ad­di­tion­al graphs (htop) and sta­tis­tics (Glances) for a more com­pre­hen­sive system analysis.

Task Manager and the “top” command not only provide numeric values and data curves to check if CPU usage is too high. Often, you’ll also be able to identify the cause.

Within Task Manager, beneath the “Processes” tab in the first table row, you can check how much of the CPU is currently being used. A breakdown of all running programs and back­ground processes can also be viewed. By clicking on the “CPU” column header, you can sort CPU according to usage intensity. If you notice a program which you hardly use but that takes up more CPU than average, you can terminate it with a right-click in the drop-down menu. This will reduce CPU usage.

The “top” command displays the CPU usage for all running processes. These can be im­me­di­ate­ly ter­mi­nat­ed using the “kill” command.

Higher than average processor usage can often be at­trib­uted to one of the following reasons:

• Programs with higher CPU re­quire­ments: Video and graphics editing programs, games with high-res­o­lu­tion graphics, DVD burning programs and ap­pli­ca­tions that convert film and photo formats, require high pro­cess­ing power and are therefore known for driving up CPU usage. If, for this reason, the computer is hardly capable of operating, you should only run these programs one at a time and close all other ap­pli­ca­tions.
• Autostart programs: Ap­pli­ca­tions that are launched by booting the operating system and that continue to run in the back­ground can affect CPU usage. That’s often the case for software required for con­nect­ing hardware com­po­nents such as cameras, MP3 players or printers. These programs will au­to­mat­i­cal­ly launch on boot-up once installed. You can prevent this from happening by de­ac­ti­vat­ing them in Task Manager via the “Autostart” tab.
• Viruses: If you notice extremely high CPU usage of nearly 100 per cent but can’t find a cause, a virus or other type of malware may be causing it. Viruses are often invisible in popular mon­i­tor­ing tools. If you suspect a virus, you should im­me­di­ate­ly check your computer with an anti-virus program or malware scanner.
• Browser: Under certain cir­cum­stances, the browser (e.g. through countless open tabs) can use up a lot of the CPU’s pro­cess­ing power. Plug-ins and add-ons that run un­de­tect­ed in the back­ground are another cause for high CPU. By regularly checking your browser settings, you can double-check if you require all the add-ons listed and de­ac­ti­vate unused or rarely used plug-ins and ex­ten­sions.

In general, high CPU usage is not a sig­nif­i­cant cause for concern as long as it doesn’t occur over the long-term or is due to an uniden­ti­fi­able cause. But there’s always the danger that your PC may freeze whilst your working on an important work as­sign­ment and that you’ll lose your unsaved data after the un­sched­uled restart. For this reason alone, you should always try to reduce high CPU usage.

A second hazard is that your CPU tem­per­a­ture will become too high. Most operating systems and proces­sors are developed in such a way that they au­to­mat­i­cal­ly protect the system from over­heat­ing, e.g. by adjusting fan speed and curbing CPU ac­tiv­i­ties – much to the dis­ap­point­ment of many gamers who specif­i­cal­ly overclock their CPUs in order to improve pro­cess­ing power.

If one of the above-mentioned causes applies, you should close the relevant programs, prefer­ably de­ac­ti­vate or uninstall them, or run them one at a time, depending on the best solution in your specific case. In general, a computer operates more quickly and smoothly if few CPU-intensive processes are running at the same time. It makes sense then, to regularly check your CPU usage so that you can terminate programs that un­nec­es­sar­i­ly burden the system, and in doing so optimize your PC’s per­for­mance.

However, if a system process is slowing down your computer, caution is advised. First of all, read up on the relevant process online to find out more about it. The same applies to processes that you cannot allocate. A quick online search may save you time and spare you issues that can emerge from ter­mi­nat­ing a process that is system-related. Doing so, you may learn more about the processes that run on your operating system.