In the Windows 11 24H2 KB5058411 update (May 2025 Patch Tuesday), Microsoft has revised the formula used to calculate CPU usage in the Task Manager’s Processes tab. The updated methodology now aligns CPU metrics in the Processes tab with those displayed in the Performance and Users tabs, resolving longstanding discrepancies and ensuring a consistent representation of processor utilization across all views.
Previously, the Processes tab employed its own distinct calculation method, resulting in noticeable differences in reported CPU usage when compared to other tabs. To address this inconsistency, Microsoft has adopted the industry-standard computation method, thereby harmonizing the data displayed throughout Task Manager.
In earlier versions, the Processes tab relied on a proprietary metric to determine processor load, while the Performance and Users tabs utilized a more precise industry-standard measurement—namely, the percentage of processor time. This divergence often led to confusion and misleading data.
Most system utilities and third-party software calculate CPU usage based on the “% Processor Time” metric, which accurately accounts for the total number of CPU cores. The legacy Processes tab, however, neglected this factor—reporting 100% usage even if only a single core was fully engaged, thereby misrepresenting the overall CPU load.
Additionally, the outdated method gauged processor utilization relative to the CPU’s base frequency. As a result, during turbo boost conditions, cores operating above base frequency could exceed 100% usage, skewing performance interpretations and suggesting throttling where none existed. These flaws rendered CPU metrics in the Processes tab inherently unreliable.
The newly implemented formula for CPU usage is as follows:
CPU % = (Δ Process CPU Time) ÷ (Δ Elapsed Time × Logical Processors)
This formula, already employed in the Performance and Users tabs, has now been extended to the Processes tab as well.
With this refinement, the CPU usage figures presented in the Processes tab—the default view when launching Task Manager—are now more accurate and consistent with those in other sections, eliminating disparities and enhancing overall reliability.
