Windows Defender, built-in security solution of the Windows operating system, slows down PCs based on 8th and 11th generation Intel processors.
The problem was discovered by Kevin Glynn, associate software author behind popular utilities such as ThrottleStop and RealTemp. While working on ThrottleStop, he noticed that the Windows Defender antivirus reduces the performance of Intel processors by 6% in Windows 10 or 11.
The bug has affected 8th and 11th generation Intel chips, but, most likely, it applies to all processors from 2007. In particular, Glyn noticed a decrease in the speed of work with his Intel Core i9-10850K processor, where Windows Defender used all the Intel Core hardware performance counters, although antiviruses usually do not use so many resources.
The developer concluded that the problem is solely caused by Windows Defender and therefore is not a fault of the Intel chips. Glynn reported the issue to Microsoft — the engineering team is expected to release a fix soon.
As a temporary measure, the specialist created the Counter Control utility, which resets the performance counters. Recently Microsoft Defender antivirus was released on iOS and macOS.