Microsoft has confirmed that users of older versions of Windows should expect to “notice a decrease in system performance” after they apply system patches to protect against the Meltdown and Spectre processor bugs.
The bugs, which affect mostly Intel processors but also some ARM and AMD chips, expose the majority of the world’s computers and phones to speculative execution side-channel attacks.
A successful attack could read portions of protected, sensitive memory, such as passwords and other secrets.
Microsoft released security updates on January 3 to fix the issue at the operating system level. Intel also issued updates for its microcode.