Confused by Task Manager’s 100% CPU usage? Windows 11 is fixing incorrect reporting

Task Manager’s all tabs (Processes, Performance and Users) will now correctly report the same CPU usage in line with industry standards and third-party apps.

But how is it getting better? Didn’t Task Manager count CPU usage correctly? It did, but it also made things confusing. Have you ever noticed that the individual process percentages didn’t add to the total?

In our tests, Windows Latest observed that something looked off even when Task Manager reported nearly 100% CPU usage and showed that the system was struggling. When you manually added up the usage reported by individual processes, it simply didn’t add up to that 100% or any other number most of the time.

This might appear to be a “bug” because it looked like Task Manager wasn’t reporting things accurately. This happened because the Processes page used a unique formula for CPU usage, while the Performance and Users pages used a different, more “industry-standard” formula.

The old Task Manager calculated CPU usage by looking at how much time a process spent running without considering the total number of CPU cores. This meant that if a process used just one core, it would show 100% usage, even if the system had multiple cores.

The Processes tab didn’t consider all CPU cores, which is why you might see 100% usage even on a multi-core system.

Meanwhile, the Performance and Users tabs used % Processor Utility. It used % Processor Utility because those tabs factored in CPU speed boosts, meaning if a processor’s base speed was 2.4 GHz but it boosted to 3.6 GHz, Task Manager could show 150% usage instead of 100%.

Windows 11 standardizes Task Manager’s CPU usage calculation

With Windows 11 Build 26120.3360, Task Manager has a new formula, which now divides the CPU usage by the total number of cores. So, for example, if an app uses one core on an 8-core system, it will now show 12.5% usage (instead of 100%).

“We are beginning to roll out a change to the way Task Manager calculates CPU utilization for the Processes, Performance, and Users pages. Task Manager will now use the standard metrics to display CPU workload consistently across all pages and aligning with industry standards and third-party tool,” Microsoft noted in a blog post.

You’ll be able to count the processes usage manually and it will match with the total usage displayed under Processes, Performance, and Users tab.

Of course, if you want to go back to the old way of counting CPU usage, you can right-click anywhere in the Task Manager and select the legacy option.

As shown in the above screenshot, the “CPU Utility” column on the Details tab (which is off by default) shows the old CPU usage formula.

Will this change be exclusive/limited to preview builds? No, Microsoft will bring it to Windows 11 24H2 and version 23H2 in a few weeks.

What else do you dislike about Task Manager? Let us know in the comments below.