Don't forget that the likely reason why the capability to change the CPUID was introduced by AMD in its processors is that Intel (mis)used the CPUID feature via

Don't forget that the likely reason why the capability to change the CPUID was introduced by AMD in its processors is that Intel (mis)used the CPUID feature via its compiler making the compiled program run faster if it runs on an Intel CPU (detected via whether CPUID is GenuineIntel, not by checking for CPU features): > https://www.agner.org/optimize/blog/read.php?i=73 https://www.agner.org/optimize/blog/read.php?i=73