Microcode updates can be applied on boot through the BIOS/EFI firmware, but also by the operating system. Linux (I don't know about Windows) has facilities to u

Microcode updates can be applied on boot through the BIOS/EFI firmware, but also by the operating system. Linux (I don't know about Windows) has facilities to update the microcode on boot: https://wiki.archlinux.org/index.php/microcode https://wiki.archlinux.org/index.php/microcode https://wiki.debian.org/Microcode https://wiki.debian.org/Microcode Also, directly from Intel: While the regular approach to getting this microcode update is via a BIOS update, Intel realizes that this can be an administrative hassle. The Linux operating system has a mechanism to update the microcode after booting. For example, this file will be used by the operating system mechanism if the file is placed in the /etc/firmware directory of the Linux system. Source: https://downloadcenter.intel.com/download/27337/Linux-Processor-Microcode-Data-File https://downloadcenter.intel.com/download/27337/Linux-Proces... Apple probably delivers them through EFI updates, but of course, getting updated EFI firmware from Apple was never a problem.