OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › Multi GPUs Calculation › Reply To: Multi GPUs Calculation June 27, 2023 at 10:57 am #7606 AdrianKeymaster Ok, this seems to be a precedence issue then – if you add -I/home/ubuntu2204/opt/openmpi/include to your CXXFLAGS and -L/home/ubuntu2204/opt/openmpi/lib to the LDFLAGS it should work.