62 Benchmarks, 12 Systems, 4 Compilers: Our Most Extensive Benchmarks Yet Of GCC vs. Clang Performance

Written by Michael Larabel in Software on 5 February 2019 at 05:00 PM EST. Page 6 of 6. 15 Comments.

In very common workloads like OpenSSL, its performance has already been studied and well-tuned by all of the compilers for the past number of years.

Redis was faster on the newer (AVX-512) CPUs with GCC where as on the other systems the performance was similar.

Interestingly in the case of Sysbench, the AMD performance was faster when built by the GCC compiler while the Intel systems performed much better with the Clang compiler.

Broadly, it's a very competitive race these days between GCC and Clang on Linux x86_64. As shown by the geometric means for all these tests, the race is neck-and-neck with GCC in some cases just having a ~2% advantage. Depending upon the particular code-base, in some cases the differences were more pronounced. One area where GCC seemed to do better on average than Clang was with the newer Core i9 7980XE and Xeon Silver systems that have AVX-512 and there the GNU Compiler Collection most often outperformed Clang. In the tests looking at the compile times, Clang still had some cases of beating out GCC but with some of the build tests the performance was close and in the case of compiling PHP it was actually faster to build on GCC.

Those wishing to dig through the 62 benchmarks across the dozen systems and the four compilers can find all of the raw performance data via this OpenBenchmarking.org result file. And if you appreciate all of our benchmarking, consider going premium.

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