Then this reviewer discovered via Reddit that Matlab includes an Intel library that doesn't generate SIMD optimized code for AMD processors. Forcing the library to generate the optimized code in an environment variable results in AMD crushing Intel with both tested processors.

It's remarkable both for AMD becoming clearly dominant in the desktop performance market, and for Intel promoting a dishonest benchmark, whether they knew it or not.

In this case their math library didn't do a CPUID feature test, but rather a vendor name test. It would be equivalent to testing website compatibility by doing a user agent check with just the browser name (e.g. navigator.userAgent.indexOf("Netscape"), etc)

ICC also historically generated intentionally bad code for non-intel platforms - deliberately making function loaded depend on intel vs. everyone else rather than by feature set.