"On the AMD side, the Clang vs. GCC performance has reached the stage that in many instances they now deliver similar performance... But in select instances, GCC still was faster: GCC was about 2% faster on the FX-8370E system and just a hair faster on the Threadripper 2990WX but with Clang 8.0 and GCC 9.0 coming just shy of their stable predecessors. These new compiler releases didn't offer any breakthrough performance changes overall for the AMD Bulldozer to Zen processors benchmarked.
On the Intel side, the Core i5 2500K interestingly had slightly better performance on Clang over GCC. With Haswell and Ivy Bridge era systems the GCC vs. Clang performance was the same. With the newer Intel CPUs like the Xeon Silver 4108, Core i7 8700K, and Core i9 7980XE, these newer Intel CPUs were siding with the GCC 8/9 compilers over Clang for a few percent better performance."
"On the AMD side, the Clang vs. GCC performance has reached the stage that in many instances they now deliver similar performance... But in select instances, GCC still was faster: GCC was about 2% faster on the FX-8370E system and just a hair faster on the Threadripper 2990WX but with Clang 8.0 and GCC 9.0 coming just shy of their stable predecessors. These new compiler releases didn't offer any breakthrough performance changes overall for the AMD Bulldozer to Zen processors benchmarked.
On the Intel side, the Core i5 2500K interestingly had slightly better performance on Clang over GCC. With Haswell and Ivy Bridge era systems the GCC vs. Clang performance was the same. With the newer Intel CPUs like the Xeon Silver 4108, Core i7 8700K, and Core i9 7980XE, these newer Intel CPUs were siding with the GCC 8/9 compilers over Clang for a few percent better performance."