There can be substantial speed boosts from Intel compilers with Intel CPUs. Intel oneAPI gives advanced debuggers and performance measurements. Intel oneMKL can give a significant speed boost to ABI-compatible compilers for certain math operations.

For Windows, use the oneAPI Command Prompt. Otherwise, specify environment variables CC, CXX, FC to indicate desired compilers, and source setvars.sh:

Build with CMake:

cmake -B build

cmake --build build

Example CMakeLists.txt

To see the compiler commands CMake is issuing, use

cmake --build build -v

Refer to Intel Link Advisor for supported compiler / operating system / MKL combinations.

Get runtime confirmation that MKL is being used via MKL_VERBOSE.

• Linux:

  MKL_VERBOSE=1 ./mytest

• Windows

  set MKL_VERBOSE=1
  mytest.exe

That gives verbose text output upon use of MKL functions. That runtime option does slow down MKL performance, so normally we don’t use it.