diff --git a/octopus/foss2021a-cuda-mpi-config.sh b/octopus/foss2021a-cuda-mpi-config.sh
index ff71c5c4f13eedf2949ac34b87079bbcd48caadf..6fd4947523088a493cf004f4d4f1d227ed207828 100644
--- a/octopus/foss2021a-cuda-mpi-config.sh
+++ b/octopus/foss2021a-cuda-mpi-config.sh
@@ -1,11 +1,12 @@
 #!/bin/sh
 export CC="mpicc"
 MARCH_FLAG="-march=${GCC_ARCH:-native}"
-export CFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+OPTIMISATION_LEVEL="-O3"
+export CFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export CXX="mpicxx"
-export CXXFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+export CXXFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export FC="mpif90"
-export FCFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
+export FCFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
 
 #HG: ugly hack to include rpath while linking
 #    becomes necessary for spack >= 0.19, as it does not set LD_LIBRARY_PATH anymore
diff --git a/octopus/foss2021a-mpi-config.sh b/octopus/foss2021a-mpi-config.sh
index 2bdc99467726d551ad21ba7516c6b349d5607c0c..8a8d39993a4739eb1beccb8c6b7be9620e0851f8 100644
--- a/octopus/foss2021a-mpi-config.sh
+++ b/octopus/foss2021a-mpi-config.sh
@@ -1,11 +1,12 @@
 #!/bin/sh
 export CC="mpicc"
 MARCH_FLAG="-march=${GCC_ARCH:-native}"
-export CFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+OPTIMISATION_LEVEL="-O3"
+export CFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export CXX="mpicxx"
-export CXXFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+export CXXFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export FC="mpif90"
-export FCFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
+export FCFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
 
 #HG: ugly hack to include rpath while linking
 #    becomes necessary for spack >= 0.19, as it does not set LD_LIBRARY_PATH anymore
diff --git a/octopus/foss2021a-serial-config.sh b/octopus/foss2021a-serial-config.sh
index 0ab100e8ee6b86aa244615bee4b4d24ed57c2644..ccf3fc4f40400180260994b3e9c8c9a49332c313 100644
--- a/octopus/foss2021a-serial-config.sh
+++ b/octopus/foss2021a-serial-config.sh
@@ -1,11 +1,12 @@
 #!/bin/sh
 export CC="gcc"
 MARCH_FLAG="-march=${GCC_ARCH:-native}"
-export CFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+OPTIMISATION_LEVEL="-O3"
+export CFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export CXX="g++"
-export CXXFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+export CXXFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export FC="gfortran"
-export FCFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
+export FCFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
 
 #HG: ugly hack to include rpath while linking
 #    becomes necessary for spack >= 0.19, as it does not set LD_LIBRARY_PATH anymore
diff --git a/octopus/foss2022a-cuda-mpi-config.sh b/octopus/foss2022a-cuda-mpi-config.sh
index ff71c5c4f13eedf2949ac34b87079bbcd48caadf..6fd4947523088a493cf004f4d4f1d227ed207828 100644
--- a/octopus/foss2022a-cuda-mpi-config.sh
+++ b/octopus/foss2022a-cuda-mpi-config.sh
@@ -1,11 +1,12 @@
 #!/bin/sh
 export CC="mpicc"
 MARCH_FLAG="-march=${GCC_ARCH:-native}"
-export CFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+OPTIMISATION_LEVEL="-O3"
+export CFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export CXX="mpicxx"
-export CXXFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+export CXXFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export FC="mpif90"
-export FCFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
+export FCFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
 
 #HG: ugly hack to include rpath while linking
 #    becomes necessary for spack >= 0.19, as it does not set LD_LIBRARY_PATH anymore
diff --git a/octopus/foss2022a-mpi-config.sh b/octopus/foss2022a-mpi-config.sh
index 2bdc99467726d551ad21ba7516c6b349d5607c0c..8a8d39993a4739eb1beccb8c6b7be9620e0851f8 100644
--- a/octopus/foss2022a-mpi-config.sh
+++ b/octopus/foss2022a-mpi-config.sh
@@ -1,11 +1,12 @@
 #!/bin/sh
 export CC="mpicc"
 MARCH_FLAG="-march=${GCC_ARCH:-native}"
-export CFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+OPTIMISATION_LEVEL="-O3"
+export CFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export CXX="mpicxx"
-export CXXFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+export CXXFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export FC="mpif90"
-export FCFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
+export FCFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
 
 #HG: ugly hack to include rpath while linking
 #    becomes necessary for spack >= 0.19, as it does not set LD_LIBRARY_PATH anymore
diff --git a/octopus/foss2022a-serial-config.sh b/octopus/foss2022a-serial-config.sh
index 4a2aaa7844e7a7e57bba98e4b5a82c8883284d0c..24a80153f56c747d15dd137750175f63ddb3be43 100644
--- a/octopus/foss2022a-serial-config.sh
+++ b/octopus/foss2022a-serial-config.sh
@@ -1,11 +1,12 @@
 #!/bin/sh
 export CC="gcc"
 MARCH_FLAG="-march=${GCC_ARCH:-native}"
-export CFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+OPTIMISATION_LEVEL="-O3"
+export CFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export CXX="g++"
-export CXXFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments"
+export CXXFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments"
 export FC="gfortran"
-export FCFLAGS="$MARCH_FLAG -O2 -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
+export FCFLAGS="$MARCH_FLAG $OPTIMISATION_LEVEL -g -fno-var-tracking-assignments -ffree-line-length-none -fallow-argument-mismatch -fallow-invalid-boz"
 
 #HG: ugly hack to include rpath while linking
 #    becomes necessary for spack >= 0.19, as it does not set LD_LIBRARY_PATH anymore