Tianyi Chen cty-yyds

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                inoryy
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              Last active
              December 28, 2022 07:54
            
              
                Fixing MKL on AMD Zen CPU.
              
          
        
      
        
  
      
    Fixing MKL on AMD Zen CPU

As per discussion on Reddit,
it seems a workaround for the Intel MKL's notorious SIMD throttling of AMD Zen CPUs is as simple a setting MKL_DEBUG_CPU_TYPE=5 environment variable.
Benchmarks

All three scripts are executed in the same Python 3.7 environment on a first-gen AMD Zen CPU (1950x).

The difference will be even bigger on newer models as first-gen Zen resolves 256-bit AVX2 in two 128-bit instructions.