GCC 11 vs. LLVM Clang 12 Performance On The Intel Core i9 11900K Is A Heated Race

Overall there is very healthy competition between GCC 11 and LLVM Clang 12 as seen on this Core i9 11900K system as well as other Intel/AMD systems we have already tried and more CPUs/systems still being benchmarked with these new compiler releases. Out of several dozen benchmarks, here is the geometric mean of all the results:

Overall, Clang 12 was about 4% faster than GCC 11.1 at the "-O2" optimization level while when hitting "-O3 -march=native" is where GCC returned to the front and was about 3% faster than Clang 12. See all of these compiler benchmarks in full with all of the data points via this OpenBenchmarking.org result file.