Is your computer running slowly, getting louder than usual or struggling with tasks it normally handles without a problem? Checking CPU usage can help you find out whether the processor is overloaded—and which application may be responsible.

You do not need to install third-party software. Windows, macOS and Linux all include built-in tools for monitoring total CPU usage and identifying CPU-intensive processes.

Quick Answer: How to Check CPU Usage

If you only need to find the program using the most processing power, sort the process list by CPU usage.

What Does CPU Usage Mean?

CPU usage shows how much of your processor’s available computing capacity is currently being used.

The percentage can change from one second to the next depending on what the computer is doing. Opening an application, installing an update, loading a website or starting a video call may cause a short spike.

CPU usage can be viewed in two ways:

• Total CPU usage: How much of the processor’s overall capacity is being used.
• Per-process CPU usage: How much processing time is being consumed by an individual application or background process.

A total percentage tells you that the computer is busy. A process list helps you identify why it is busy.

How to Check CPU Usage on Windows 11 and Windows 10

Task Manager is the fastest way to check CPU usage on Windows. Microsoft describes it as a system-monitoring tool that displays CPU load, memory consumption, disk activity and network usage.

Method 1: Check CPU Usage in Task Manager

1. Press Ctrl + Shift + Esc.
2. If Task Manager opens in a simplified view, select More details.
3. Open the Processes section.
4. Find the CPU column.
5. Click the CPU heading to sort processes from highest to lowest usage.

The percentage at the top of the CPU column represents total CPU usage. The values underneath show which applications and background processes are consuming processor resources.

You can also open Task Manager by right-clicking the Start button and selecting Task Manager. These methods are documented in Microsoft’s Windows system configuration guide.

How to Identify a CPU-Heavy Program

Click the CPU column until the highest value appears at the top.

Before closing a process, check its name carefully. A browser, game, video editor or compression tool may legitimately use significant processing power. Avoid ending Windows processes or services you do not recognize.

If an application is unresponsive and you are certain it is safe to close:

1. Select the application in Task Manager.
2. Save your work in other applications.
3. Select End task.

Ending a task may cause unsaved data in that application to be lost.

Method 2: View Total and Per-Core CPU Usage

The Performance page provides more information about the processor.

1. Open Task Manager.
2. Select Performance.
3. Select CPU.

You can now see:

• Current CPU utilization;
• Processor speed;
• Number of processes and threads;
• System uptime;
• Core and logical processor count;
• A graph of CPU activity over time.

Microsoft also uses the Task Manager Performance page as the standard method for checking processor and core information in Windows. See Microsoft’s processor core guide.

To view activity for each logical processor:

1. Right-click the CPU graph.
2. Select Change graph to.
3. Select Logical processors.

This view is useful when an application depends heavily on one or two threads. Total CPU usage may appear moderate even though one logical processor is operating near its limit.

Method 3: Check CPU Usage with Resource Monitor

Resource Monitor provides a more detailed view of CPU activity, processes, services and process associations.

To open it:

1. Press Windows + R.
2. Enter resmon.
3. Press Enter.
4. Open the CPU tab.

Alternatively, search for Resource Monitor from the Start menu.

Resource Monitor is particularly useful when:

• A background service is consuming CPU;
• Several processes have similar names;
• You want to see which services belong to a process;
• CPU usage remains high but the cause is unclear in Task Manager.

Microsoft recommends sorting processes by CPU usage and using Resource Monitor during more detailed investigations of sustained high processor load. See the company’s high CPU usage troubleshooting guidance.

Method 4: Check CPU Usage with PowerShell

Advanced users can collect CPU usage data from PowerShell.

Open PowerShell and run:

Get-Counter -Counter "\Processor(_Total)\% Processor Time" -SampleInterval 2 -MaxSamples 5

This takes five samples at two-second intervals.

To continue monitoring until you stop the command, use:

Get-Counter -Counter "\Processor(_Total)\% Processor Time" -Continuous

Press Ctrl + C to stop monitoring.

Microsoft notes that Get-Counter retrieves Windows performance counter data and that counter names may be localized on non-English Windows installations. If the command does not recognize the English counter name, use the following command to view the counter sets available on your system:

Get-Counter -ListSet *

See Microsoft’s Get-Counter documentation.

How to Check CPU Usage on a Mac

macOS includes Activity Monitor, which displays CPU, memory, energy, disk and network activity.

Check CPU Usage in Activity Monitor

1. Press Command + Space to open Spotlight.
2. Type Activity Monitor.
3. Press Return.
4. Select the CPU tab.
5. Click the % CPU column to sort processes from highest to lowest usage.

At the bottom of the window, Activity Monitor separates CPU activity into:

• System: CPU capacity used by macOS processes;
• User: CPU capacity used by applications and their related processes;
• Idle: CPU capacity that is not currently being used.

Apple explains these measurements in its official Activity Monitor CPU guide.

View CPU Usage Over Time on a Mac

With Activity Monitor open, select:

• Window → CPU Usage to view current activity;
• Window → CPU History to view recent processor activity.

You can also select View → Dock Icon and choose a CPU display option to monitor processor activity from the Dock.

How to Close a CPU-Heavy Process on a Mac

If you recognize an application that is unresponsive or using excessive CPU:

1. Select the process.
2. Click the Stop button.
3. Choose Quit first.
4. Use Force Quit only if the process does not respond.

Save your work before closing an application. Do not force-quit macOS system processes unless you understand their function.

How to Check CPU Usage on Linux

Linux users can monitor CPU usage with graphical utilities or terminal commands. The exact tools available depend on the distribution and desktop environment.

Method 1: Check CPU Usage with top

Open a terminal and run:

top

The upper section displays system-wide information, while the process table shows individual processes.

Look for:

• %Cpu(s) for overall CPU activity;
• %CPU for the processor usage of each process;
• PID for the process ID;
• COMMAND for the process name.

Useful keyboard controls inside top include:

• Press P to sort processes by CPU usage;
• Press 1 to switch between combined and per-CPU statistics;
• Press q to exit.

The Linux top manual defines %CPU as a task’s share of elapsed CPU time since the previous screen update. On multicore systems, a multithreaded process may sometimes display more than 100%, depending on the display mode. See the top Linux manual page.

Method 2: Use htop for a More Visual Display

htop provides a more interactive process list with coloured CPU meters and keyboard navigation.

Run:

htop

If it is not installed, use the package manager provided by your distribution.

For Ubuntu and Debian-based systems:

sudo apt update
sudo apt install htop

For Fedora:

sudo dnf install htop

For Arch Linux:

sudo pacman -S htop

After opening htop, select or click the CPU column to sort processes. Press F10 or q to exit.

Package names and installation commands may vary by distribution.

Method 3: Check CPU Usage Per Core with mpstat

The mpstat command reports processor statistics and is useful when you need to check individual logical CPUs.

Run:

mpstat -P ALL 1

In this command:

• -P ALL displays every available processor;
• 1 refreshes the report every second;
• %idle shows the percentage of time a CPU was idle.

A low %idle value means that the processor was busy during that interval.

If mpstat is not installed on Ubuntu or Debian, install the sysstat package:

sudo apt update
sudo apt install sysstat

According to the mpstat manual, the tool can report both per-processor activity and an average across all processors.

Method 4: List the Processes Using the Most CPU

Run:

ps -eo pid,comm,%cpu,%mem --sort=-%cpu | head

This displays a short list of processes sorted by CPU usage.

Keep in mind that ps does not provide the same live measurement as top. Its %CPU value is based on CPU time relative to how long the process has been running. The ps manual explains that these values may not add up to exactly 100%.

Use top or htop when you need real-time monitoring. Use ps when you need a quick, script-friendly process list.

What Is a Normal CPU Usage?

There is no single CPU percentage that is normal for every computer.

Expected usage depends on:

• The processor and number of cores;
• The operating system;
• Applications running in the foreground;
• Background updates and security scans;
• Browser tabs and extensions;
• Games, virtual machines and creative workloads;
• Power and cooling limits.

A mostly idle computer should normally leave substantial processor capacity unused. However, a short spike while opening an application or loading a page is not automatically a problem.

Higher usage is expected during:

• Gaming;
• Video rendering or encoding;
• Software compilation;
• File compression;
• Operating system updates;
• Antivirus scans;
• Virtual machine workloads.

Investigate further when high CPU usage:

• Continues after the workload has finished;
• Occurs when the computer should be idle;
• Causes persistent freezing or stuttering;
• Makes applications repeatedly stop responding;
• Appears together with unusually high temperatures or frequent performance drops.

Why Is My CPU Usage So High?

High total CPU usage does not always mean the processor itself is faulty. In many cases, one application, service or background task is responsible.

How to Reduce High CPU Usage

Work through these steps in order.

1. Identify the Process

Use Task Manager, Activity Monitor, top or htop to find the process consuming the most CPU.

Do not end an unfamiliar system process just because it appears near the top.

2. Wait for Temporary Tasks to Finish

Updates, indexing, software installation and security scans may temporarily use substantial processing power. If the process is legitimate, allowing it to finish may be safer than interrupting it.

3. Close and Reopen the Application

Save your work, close the CPU-heavy application and open it again. This may resolve a temporary software problem.

4. Restart the Computer

A restart clears stuck processes and completes some pending updates. Check CPU usage again before reopening all your usual applications.

5. Update the System and Applications

Install stable updates for the operating system, applications and relevant device drivers. If high usage began immediately after an update, check the vendor’s support information before making further changes.

6. Reduce Background and Startup Programs

Disable applications you do not need to launch automatically. Avoid disabling security software or essential hardware services without understanding their purpose.

7. Check Cooling and Ventilation

Keep the air vents clear and place the computer on a hard, stable surface. Dust buildup or restricted airflow can increase temperature and reduce sustained performance.

CPU usage and CPU temperature are different measurements. A processor can be fully utilised without overheating, while cooling problems can affect performance even when utilisation is below 100%.

8. Check Whether the Hardware Matches the Workload

If the CPU remains fully occupied during routine work—even after removing unnecessary background tasks—the processor may not provide enough performance for that workload.

This is more relevant when you regularly use:

• Large spreadsheets and data tools;
• Many browser tabs alongside video conferencing;
• Software development and compilation;
• Virtual machines or containers;
• Photo and video editing;
• Local media servers;
• CPU-intensive games.

When Does High CPU Usage Mean You Need a Faster Mini PC?

Do not replace a computer because of one brief CPU spike. First identify the process, check for software problems and confirm that cooling is working correctly.

A faster system may be worth considering when:

• Normal daily tasks repeatedly push the CPU to its limit;
• The same workloads remain slow after software troubleshooting;
• Multitasking consistently causes freezing or delayed input;
• Your applications require more cores or threads;
• The existing system cannot maintain the performance you need.

When choosing a Mini PC, consider the complete workload rather than the CPU name alone. Core count, sustained cooling, memory capacity and storage performance can all affect responsiveness.

For everyday web browsing and office work, an efficient entry-level processor may be sufficient. Development, content creation, virtualisation and demanding multitasking generally benefit from a higher-performance multicore processor.

Explore NIPOGI Mini PCs for home, office and multitasking, or read our guide to measuring actual CPU power consumption to understand the difference between processor utilisation and power use.

Frequently Asked Questions

Is 100% CPU usage bad?

Not necessarily. CPU usage can briefly reach 100% when launching an application, installing updates, rendering video or running another demanding task.

It becomes a concern when it remains at 100% for an extended period, occurs without an obvious workload or causes persistent slowdowns and instability.

How do I see which program is using the CPU?

On Windows, open Task Manager and sort the CPU column. On a Mac, open Activity Monitor and sort by % CPU. On Linux, run top and press P, or use htop.

How do I check CPU usage per core?

On Windows, open Task Manager → Performance → CPU, right-click the graph and select Logical processors.

On macOS, open Activity Monitor and select Window → CPU History.

On Linux, run:

mpstat -P ALL 1

You can also press 1 while using top.

Why is CPU usage high when no applications are open?

Visible application windows are not the only processes running on a computer. Updates, indexing, cloud synchronisation, security scans, browser background processes and system services may continue running.

Sort the process list by CPU usage to identify the cause before changing settings.

What is the difference between CPU usage and CPU temperature?

CPU usage measures how much processor capacity is currently being used. CPU temperature measures how hot the processor is.

High usage can increase temperature, but they are not interchangeable measurements.

Is Linux load average the same as CPU usage?

No. CPU usage is expressed as processor activity over a particular period. Load average represents the average number of tasks that are running or waiting for resources over time.

Do not interpret a load average value as a CPU percentage.

Can I check CPU usage without installing software?

Yes. Task Manager, Activity Monitor and top are built into Windows, macOS and most Linux systems respectively. Additional tools such as htop and mpstat are optional.

Final Takeaway

The quickest way to check CPU usage is:

• Windows: Ctrl + Shift + Esc;
• Mac: Activity Monitor → CPU;
• Linux: Run top.

Start by checking total usage, then sort processes to find what is consuming the processor. Brief spikes are common; sustained high usage that causes slowdowns deserves further investigation.