Windows 11: Microsoft corrects a 20 -year -old bug in the task manager

We were talking about it recently, in its last May 2025 update, Microsoft discreetly revised the way the task manager assesses the use of the processor. Until then, the “Process” tab was playing its own score, generating sometimes absurd deviations with the “Performance” and “Users” tabs.

It is now ancient history: The 24h2 version unifies calculation methods. An advance greeted, without closing the door to those who preferred the old formula.

Windows 11: A new smarter method to measure CPU use in the task manager

Microsoft has not made a whole dish, and yet it is a small revolution for those who scrutinize their processor with a magnifying glass. With the Patch KB5058411, Windows 11 Replaces in the task manager process tab its old house formula – the famous PROCESOR UTILITY – by a method now aligned with standards in the sector.

So far, this old formula simply ignored the number of logical hearts. Result: a single saturated heart could be enough to display a 100 %CPU, completely distorting the overall load perception. This obsolete metric could also exceed 100 % in the event of high frequencies (thank you Turbo Boost), making data more opaque than really useful.

From now on, the three tabs (process, performance, users) are based on the same calculation basis: CPU % = (CPU time used) ÷ (time elapsed × number of logical cores). Direct consequence: the figures displayed are consistent from one tab to another, and much more faithful to reality. To diagnose slowdowns or monitor an abnormal load, it is a real relief.

And for those who love the old method? Microsoft has thought of them: in the Details tab, a right click on a column header allows you to activate CPU Utility to find old values. A small adjustment for Redmond, but great progress for the legibility of performance.