diff --git a/tests/TEST_DIRS b/tests/TEST_DIRS
index 98cf3a9f49..c90de5bfe9 100644
--- a/tests/TEST_DIRS
+++ b/tests/TEST_DIRS
@@ -3,276 +3,276 @@
 # Directories have been reordered according the execution time needed for a gfortran pdbg run using 2 MPI tasks
 # in case a new directory is added just add it at the top of the list..
 # the order will be regularly checked and modified...
-QS/regtest-grid
-QS/regtest-corr_dipm
-QS/regtest-admm-gapw                                        libint
-QS/regtest-rs-dhft                                          libint libxc
-QS/regtest-sos-mp2-lr                                       libint
-QS/regtest-rpa-lr                                           libint
-QS/regtest-mp2-lr                                           libint
-QS/regtest-xastdp                                           libint libxc
-QS/regtest-gw2x                                             libint libxc
-QS/regtest-negf
-QS/regtest-negf-fft                                         fftw3
-QS/regtest-ri-rpa-axk                                       libint
-QS/regtest-ri-rpa-rse                                       libint
-QS/regtest-cdft-hirshfeld-2                                 parallel mpiranks>1
-QS/regtest-cdft-hirshfeld
-SIRIUS/regtest-1                                            sirius
-QS/regtest-embed                                            libint
-QS/regtest-pod
-QS/regtest-debug-1
-QS/regtest-debug-2                                          libint
-QS/regtest-debug-3                                          libint
-QS/regtest-cdft-diag
-xTB/regtest-1
-xTB/regtest-2
-xTB/regtest-3
-xTB/regtest-4
-xTB/regtest-5
-xTB/regtest-debug
-QS/regtest-almo-strong
-QS/regtest-elpa-2                                           elpa
-QS/regtest-cdft-5
-Pimd/regtest-1
-Pimd/regtest-2
-QS/regtest-mp2-grad                                         libint
-QS/regtest-kp-2
-QS/regtest-pao-2
-QS/regtest-tddfpt-2                                         libint
-QS/regtest-tddfpt-3
-QS/regtest-p-efield
-QS/regtest-mp2-stress                                       libint
-QS/regtest-ri-rpa                                           libint
-QS/regtest-kg                                               libxc
-QS/regtest-ec                                               libint
-QS/regtest-gpw-4
-QS/regtest-gpw-8
-QS/regtest-gpw-2-3
-QS/regtest-sccs-3
-QS/regtest-gpw-5
-QS/regtest-hfx                                              libint
-QS/regtest-hfx-2                                            libint
-Fist/regtest-7-1
-QS/regtest-mom-2                                            libint
-QS/regtest-gw                                               libint
-QS/regtest-rel
-QS/regtest-admm-qps                                         libint
-QS/regtest-sccs-1
-QS/regtest-kp-1                                             libint
-QS/regtest-kp-3
-QS/regtest-slab
-ATOM/regtest-pseudo
-DFTB/regtest-scc
-DFTB/regtest-scc-2
-DFTB/regtest-debug
-QS/regtest-gpw-3
-QS/regtest-ot
-QS/regtest-gpw-1                                            libint
-QS/regtest-ps-implicit-2-1
-QS/regtest-rtp-3
-QS/regtest-dft-vdw-corr-3                                   libxc
-Fist/regtest-opt
-QS/regtest-hfx-block                                        libint
-QS/regtest-ls-rtp
-QMMM/SE/regtest-force-mixing
-QS/regtest-xc
-QS/regtest-hfx-wfn-fitting                                  libint libxc
-QS/regtest-tddfpt
-QS/regtest-tddfpt-stda                                      libint
-QS/regtest-libxc                                            libxc libint
-QS/regtest-ps-implicit-2-2
-QMMM/QS/regtest-1
-QS/regtest-gpw-6-2
-Fist/regtest-12
-QS/regtest-lvlshift
-QS/regtest-plus_u
-QS/regtest-ps-implicit-1-3                                  fftw3
-QS/regtest-admm-4                                           libint
-ATOM/regtest-1
-QS/regtest-gw-ic-model                                      libint
-QS/regtest-almo-md
-QS/regtest-pao-1
-QS/regtest-ri-mp2                                           libint
-QS/regtest-almo-2
-QS/regtest-nonortho
-QS/regtest-gapw-4                                           libint
-QMMM/SE/regtest
-Fist/regtest-7-2
-QS/regtest-nmr-uks-1
-QS/regtest-hfx-periodic                                     libint
-QS/regtest-hybrid-4                                         libint libxc
-QS/regtest-gapw
-QS/regtest-nmr-6
-QS/regtest-ot-1
-QMMM/QS/regtest-cdft                                        parallel mpiranks==2||mpiranks==4||mpiranks==6||mpiranks==16||mpiranks==24
-SE/regtest-2-2
-QS/regtest-gapw-1
-QS/regtest-ps-implicit-1-1                                  fftw3
-QS/regtest-pao-4
-QS/regtest-kind
-QS/regtest-polar
-Fist/regtest-5
-QS/regtest-nmr-1
-QS/regtest-ot-2
-QS/regtest-almo-1
-Fist/regtest-1-4
-SE/regtest-3-4
-QS/regtest-mp2-3                                            libint
-QS/regtest-sccs-2
-QS/regtest-dm-ls-scf-3
-QS/regtest-hole-funct
-MC/regtest
-SE/regtest-3-2
-QS/regtest-bs
-QS/regtest-dft-filtermat
-QS/regtest-nmr-4
-QS/regtest-gpw-7
-Fist/regtest-pol
-Fist/regtest-6
-QS/regtest-ps-implicit-1-2                                  fftw3
-SE/regtest-2-1
-QS/regtest-dft-vdw-corr-2                                   libxc libint
-QS/regtest-sparsity                                         libint
-QS/regtest-admm-2                                           libint
-QS/regtest-double-hybrid-2                                  libint
-SE/regtest
-QS/regtest-dm-ls-scf-1
-QS/regtest-admm-dm                                          libint
-QS/regtest-md-extrap
-QS/regtest-double-hybrid-3                                  libint
-QS/regtest-ps-implicit-2-3
-QS/regtest-gpw-2-2
-QS/regtest-epr-1
-Fist/regtest-4
-Fist/regtest-3
 QS/regtest-rma                                              libint mpi3 mpiranks==4
-QS/regtest-hybrid-3                                         libint
-Fist/regtest-excl-R
-QMMM/QS/regtest-3
-Fist/regtest-excl-G
-ATOM/regtest-2
-QS/regtest-lrigpw
-QS/regtest-lrigpw-2
-QS/regtest-admm-3                                           libint
-QS/regtest-cdft-3                                           parallel mpiranks==2||mpiranks==4||mpiranks==6||mpiranks==16||mpiranks==24
-QS/regtest-gw-cubic                                         libint
-QS/regtest-double-hybrid-1                                  libint
-QS/regtest-mp2-4                                            libint
-QS/regtest-sym-3
-QS/regtest-gpw-6-4
-LIBTEST
 LIBTEST/libvori                                             libvori
 LIBTEST/libbqb                                              libbqb
-Fist/regtest-5-vib                                          mpiranks==1||mpiranks==2||mpiranks==4
-QS/regtest-hfx-stress                                       libint
-QS/regtest-admm-1                                           libint
-QS/regtest-sym-4
-QS/regtest-sym-2
-QS/regtest-gapw-3
-QS/regtest-sym-5
-QS/regtest-ri-laplace-mp2                                   libint
-QS/regtest-pexsi                                            pexsi
-QS/regtest-sym-1
 QS/regtest-rma-3D                                           libint mpi3 mpiranks==8
+TMC/regtest_ana_on_the_fly                                  parallel mpiranks>2
+TMC/regtest                                                 parallel mpiranks>1
+TMC/regtest_ana_post_proc                                   parallel mpiranks>1
+xTB/regtest-5
+Pimd/regtest-1
+Pimd/regtest-2
+QS/regtest-pao-2
+QS/regtest-embed                                            libint
 QS/regtest-rpa-cubic-scaling                                libint
-QS/regtest-cdft-4-3
-Fist/regtest-1-2
-Fist/regtest-1-3
-QS/regtest-rtp-2
-QS/regtest-gpw-6-3
+QS/regtest-kp-2
+QS/regtest-admm-gapw                                        libint
+DFTB/regtest-scc-2
+QS/regtest-p-efield
+QS/regtest-debug-1
+QS/regtest-debug-2                                          libint
+QS/regtest-gpw-4
+SIRIUS/regtest-1                                            sirius
+QS/regtest-pod
+QS/regtest-gpw-2-3
+DFTB/regtest-scc
+QS/regtest-xastdp                                           libint libxc
+QS/regtest-hfx                                              libint
+QS/regtest-cdft-diag
+QS/regtest-rel
+QS/regtest-debug-3                                          libint
+QS/regtest-gw2x                                             libint libxc
+QS/regtest-ls-rtp
+QS/regtest-admm-qps                                         libint
+ATOM/regtest-pseudo
+Fist/regtest-7-1
+QMMM/SE/regtest-force-mixing
+QS/regtest-gpw-8
+xTB/regtest-1
+QS/regtest-ot
+QS/regtest-mp2-grad                                         libint
+QS/regtest-plus_u
+QS/regtest-gpw-3
+QS/regtest-ps-implicit-1-3                                  fftw3
+QS/regtest-ec                                               libint
+QS/regtest-ps-implicit-2-2
+QS/regtest-rtp-3
+QS/regtest-pao-1
+QMMM/QS/regtest-1
+QS/regtest-ps-implicit-2-1
+QS/regtest-as-1                                             libint
+xTB/regtest-2
+Fist/regtest-12
+QS/regtest-kg                                               libxc
+QS/regtest-ri-rpa                                           libint
+QS/regtest-nmr-uks-1
+QS/regtest-libxc                                            libxc libint
+SE/regtest-3-2
+QS/regtest-gw-cubic                                         libint
+QS/regtest-xc
+QS/regtest-almo-2
+SE/regtest-2-2
+QS/regtest-kp-1                                             libint
+QS/regtest-ri-rpa-axk                                       libint
+QS/regtest-gapw-1
+QS/regtest-hfx-wfn-fitting                                  libint libxc
+QS/regtest-lvlshift
+QS/regtest-gapw
+QMMM/SE/regtest
+QS/regtest-hfx-periodic                                     libint
+QS/regtest-tddfpt-stda                                      libint
+Fist/regtest-opt
+QS/regtest-nmr-6
+QS/regtest-gpw-1                                            libint
+QS/regtest-gapw-4                                           libint
+MC/regtest
+QS/regtest-ri-mp2                                           libint
+QS/regtest-negf-fft                                         fftw3
+QS/regtest-dft-vdw-corr-3                                   libxc
+QS/regtest-admm-4                                           libint
+xTB/regtest-debug
+Fist/regtest-1-4
+QS/regtest-negf
+QS/regtest-hfx-ri                                           libint
+QS/regtest-almo-md
+QS/regtest-tddfpt-2                                         libint
+SE/regtest-2-1
+QS/regtest-lrigpw-2
+QS/regtest-pao-4
+SE/regtest-3-4
+Fist/regtest-pol
+QS/regtest-nmr-4
+QMMM/QS/regtest-cdft                                        parallel mpiranks==2||mpiranks==4||mpiranks==6||mpiranks==16||mpiranks==24
+QS/regtest-gw                                               libint
+QS/regtest-ps-implicit-1-1                                  fftw3
+QS/regtest-mp2-stress                                       libint
+QS/regtest-rpa-lr                                           libint
+QS/regtest-nmr-1
+QS/regtest-ot-1
 Fist/regtest-15
-QS/regtest-hybrid-2                                         libint
+QS/regtest-tddfpt-3
+SE/regtest
+QS/regtest-dft-vdw-corr-2                                   libxc libint
+QS/regtest-epr-1
+QS/regtest-lrigpw
+Fist/regtest-5
+xTB/regtest-3
+Fist/regtest-6
+QS/regtest-hybrid-4                                         libint libxc
+QS/regtest-mom-2                                            libint
+QS/regtest-hfx-block                                        libint
+QS/regtest-ps-implicit-1-2                                  fftw3
+QS/regtest-slab
+QS/regtest-admm-1                                           libint
+QS/regtest-gpw-5
+QS/regtest-admm-3                                           libint
+QS/regtest-kind
+QS/regtest-gapw-3
+QS/regtest-dm-ls-scf-3
+QS/regtest-ps-implicit-2-3
+QS/regtest-almo-1
+QS/regtest-admm-2                                           libint
+QS/regtest-admm-dm                                          libint
+Fist/regtest-5-vib                                          mpiranks==1||mpiranks==2||mpiranks==4
+QS/regtest-pexsi                                            pexsi
+QS/regtest-ot-2
+Fist/regtest-7-2
+QS/regtest-mp2-lr                                           libint
+QS/regtest-sparsity                                         libint
+QS/regtest-polar
+QS/regtest-grid
+SE/regtest-4
+QS/regtest-nonortho
+QS/regtest-hybrid-3                                         libint
+QS/regtest-almo-trustr
+QS/regtest-gpw-6-2
+QS/regtest-md-extrap
+QS/regtest-gpw-2-2
+QS/regtest-corr_dipm
+LIBTEST
+QS/regtest-rtp-2
+QS/regtest-hfx-stress                                       libint
+Fist/regtest-3
+QS/regtest-dm-ls-scf-1
+QMMM/QS/regtest-2-erf
+QS/regtest-nmr-5
+QS/regtest-hole-funct
+QS/regtest-sccs-1
+QS/regtest-bs
+QS/regtest-tddfpt
+QMMM/QS/regtest-3
+QS/regtest-sccs-3
+ATOM/regtest-1
+QS/regtest-ri-laplace-mp2                                   libint
+NNP/regtest-1
+QS/regtest-cdft-5
+QS/regtest-gpw-7
+QS/regtest-sos-mp2-lr                                       libint
+Fist/regtest-1-3
+QS/regtest-almo-strong
+QS/regtest-stress
+QMMM/QS/regtest-2-swave
+QS/regtest-cdft-4-3
+QS/regtest-cdft-3                                           parallel mpiranks==2||mpiranks==4||mpiranks==6||mpiranks==16||mpiranks==24
+Fist/regtest-4
+Fist/regtest-1-2
+QS/regtest-ri-laplace-mp2-cubic                             libint
+QMMM/QS/regtest-image
+QS/regtest-gpw-6-4
+QS/regtest-mp2-4                                            libint
+QS/regtest-ot-1-vib                                         mpiranks==1||mpiranks==2||mpiranks==4
+Fist/regtest-2
+QS/regtest-mp2-2                                            libint
+QMMM/QS/regtest-gapw                                        libint
 QS/regtest-dm-ls-scf-2
+QS/regtest-mp2-3                                            libint
+QS/regtest-hybrid-2                                         libint
+QS/regtest-chi-1
 QS/regtest-cdft-4-2
 DFTB/regtest-nonscc
-Fist/regtest-2
-SE/regtest-4
-QS/regtest-nmr-5
-QMMM/QS/regtest-shell-pol
-TMC/regtest_ana_on_the_fly                                  parallel mpiranks>2
-QS/regtest-stress
-QS/regtest-hirshfeld
-QMMM/QS/regtest-image
+QS/regtest-double-hybrid-3                                  libint
+QS/regtest-dft-filtermat
+SE/regtest-3-3
+ATOM/regtest-2
 NEB/regtest-4
-QS/regtest-meta
-QS/regtest-mp2-2                                            libint
-QS/regtest-ot-refine-2
-QS/regtest-gpw-2-1
+QS/regtest-kp-3
+xTB/regtest-4
+QS/regtest-ri-rpa-rse                                       libint
 QS/regtest-dft-vdw-corr-1
-QMMM/DFTB/regtest
+QS/regtest-epr-2
+QS/regtest-gw-ic-model                                      libint
+QS/regtest-rs-dhft                                          libint libxc
+QS/regtest-meta
 QMMM/xTB/regtest
 QS/regtest-gpw-9                                            libxc
-QMMM/QS/regtest-gapw                                        libint
-QS/regtest-cdft-4-1
+QS/regtest-double-hybrid-1                                  libint
+QS/regtest-nlmo
 QMMM/QS/regtest-4
-TMC/regtest                                                 parallel mpiranks>1
-Fist/regtest-1-1
-QS/regtest-chi-1
-Fist/regtest-14
-Fist/regtest-10
-QS/regtest-ot-refine
-QS/regtest-cdft-1
+Fist/regtest-8
+QS/regtest-cdft-4-1
 QMMM/SE/regtest_2
 QS/regtest-mp2-1                                            libint
-QS/regtest-gapw-2
-QMMM/QS/regtest-2-erf
+QMMM/DFTB/regtest
+Fist/regtest-10
+QS/regtest-sccs-2
+QS/regtest-gpw-6-3
+QS/regtest-sym-4
 QS/regtest-md-lgvregion
-QMMM/QS/regtest-2-swave
-Fist/regtest-8
-QS/regtest-cdft-2
+QS/regtest-hirshfeld
 QS/regtest-almo-eda
-Fist/regtest-gauss
-SE/regtest-3-3
-QS/regtest-epr-2
-QS/regtest-ot-1-vib                                         mpiranks==1||mpiranks==2||mpiranks==4
-QS/regtest-elpa-qr                                          elpa mpiranks==1||mpiranks==2||mpiranks==4||mpiranks==6||mpiranks==8
-QS/regtest-all-electron
-QS/regtest-hybrid-1                                         libint
-FARMING/regtest-1
-TMC/regtest_ana_post_proc                                   parallel mpiranks>1
-FE/regtest-1
-Fist/regtest-9
-QS/regtest-ot-refine-3
-Fist/regtest-11
-QS/regtest-as                                               libint
-QS/regtest-rtp-1
-Fist/regtest-13
-QS/regtest-nmr-3
-NEB/regtest-2
-QS/regtest-cdft-3-1
-QS/regtest-mom-1
-NEB/regtest-1
-QS/regtest-pao-3
-optimize_input/regtest-1
-QS/regtest-spin-spin-1
-QS/regtest-properties/resp
-QS/regtest-nmr-2
-SE/regtest-3-1
-Fist/regtest-field
-FE/regtest-3
-QS/regtest-optbas
-QS/regtest-elpa                                             elpa mpiranks==1||mpiranks==2||mpiranks==4||mpiranks==6||mpiranks==8||mpiranks==16
-QS/regtest-linearscaling
-SWARM/regtest-glbopt-1
-TAMC/regtest
-QS
-NEB/regtest-3
-QS/regtest-lsroks
-QMMM/QS/regtest-lrigpw
-FE/regtest-2
-QS/regtest-fftw                                             fftw3
-Fist/regtest-quip                                           quip
-ATOM/regtest-libxc                                          libxc
-Fist/regtest-plumed2                                        plumed2
-QS/regtest-sto
-QS/regtest-ri-laplace-mp2-cubic                             libint
+QS/regtest-gpw-2-1
+QS/regtest-cdft-1
+QS/regtest-ot-refine
+QS/regtest-gapw-2
 QS/regtest-dm-ls-scf-4
-QS/regtest-almo-trustr
-QS/regtest-nlmo
-QS/regtest-hfx-ri                                           libint
-Fist/regtest-gal19
-NNP/regtest-1
-QS/regtest-as-1                                             libint
+Fist/regtest-1-1
+QS/regtest-all-electron
+QMMM/QS/regtest-shell-pol
+QS/regtest-double-hybrid-2                                  libint
+Fist/regtest-excl-R
+Fist/regtest-14
+QS/regtest-cdft-hirshfeld-2                                 parallel mpiranks>1
+Fist/regtest-excl-G
+FE/regtest-1
+QS/regtest-hfx-2                                            libint
+QS/regtest-nmr-3
+QS/regtest-hybrid-1                                         libint
+QS/regtest-rtp-1
+QS/regtest-as                                               libint
+QS/regtest-sym-3
+FARMING/regtest-1
+QS/regtest-cdft-2
+QS/regtest-sym-1
+QS/regtest-sym-2
+QS/regtest-ot-refine-2
+NEB/regtest-2
+QS/regtest-nmr-2
+QS/regtest-cdft-3-1
+QS/regtest-cdft-hirshfeld
+QS/regtest-optbas
+QS/regtest-spin-spin-1
+QS/regtest-elpa-qr                                          elpa mpiranks==1||mpiranks==2||mpiranks==4||mpiranks==6||mpiranks==8
+QS/regtest-ot-refine-3
+QS/regtest-sym-5
+Fist/regtest-9
+QS/regtest-mom-1
+TAMC/regtest
+Fist/regtest-13
+NEB/regtest-1
+QS
+Fist/regtest-11
+FE/regtest-3
 QS/regtest-spgr                                             spglib
+QS/regtest-sto
+SWARM/regtest-glbopt-1
+QS/regtest-properties/resp
+QS/regtest-pao-3
+DFTB/regtest-debug
+optimize_input/regtest-1
+FE/regtest-2
+QS/regtest-lsroks
+NEB/regtest-3
+QS/regtest-linearscaling
+SE/regtest-3-1
+QMMM/QS/regtest-lrigpw
+Fist/regtest-field
+Fist/regtest-gauss
+QS/regtest-elpa-2                                           elpa
+Fist/regtest-gal19
+QS/regtest-fftw                                             fftw3
+QS/regtest-elpa                                             elpa mpiranks==1||mpiranks==2||mpiranks==4||mpiranks==6||mpiranks==8||mpiranks==16
+ATOM/regtest-libxc                                          libxc
 Fist/regtest-spgr                                           spglib
+Fist/regtest-plumed2                                        plumed2
+Fist/regtest-quip                                           quip
diff --git a/tools/docker/scripts/test_python.sh b/tools/docker/scripts/test_python.sh
index 31ba7c2982..535342ca7e 100755
--- a/tools/docker/scripts/test_python.sh
+++ b/tools/docker/scripts/test_python.sh
@@ -25,6 +25,7 @@ echo ""
 run_test ./tools/prettify/prettify_test.py
 run_test mypy --strict ./tools/dashboard/generate_dashboard.py
 run_test mypy --strict ./tools/regtesting/do_regtest.py
+run_test mypy --strict ./tools/regtesting/optimize_test_dirs.py
 
 # Test generate_dashboard.py. Running it twice to also execute its caching.
 mkdir -p /workspace/artifacts/dashboard
diff --git a/tools/regtesting/optimize_test_dirs.py b/tools/regtesting/optimize_test_dirs.py
new file mode 100755
index 0000000000..c444033230
--- /dev/null
+++ b/tools/regtesting/optimize_test_dirs.py
@@ -0,0 +1,53 @@
+#!/usr/bin/python3
+
+# author: Ole Schuett
+
+import argparse
+from pathlib import Path
+import re
+
+
+# ======================================================================================
+def main() -> None:
+    parser = argparse.ArgumentParser(description="Sorts the test dirs by duration.")
+    parser.add_argument("regtest_report")
+    args = parser.parse_args()
+
+    report = Path(args.regtest_report).read_text(encoding="utf8")
+    match = re.search(">>> (.*?)/UNIT\n", report)
+    assert match
+    report_basedir = match.group(1)
+
+    timings = {}
+    for line in re.findall("<<< (.*?)\n", report):
+        parts = line.split()
+        name = parts[0][len(report_basedir) + 1 :]
+        timings[name] = float(parts[6])
+
+    cp2k_root = Path(__file__).resolve().parent.parent.parent
+    test_dirs_fn = cp2k_root / "tests" / "TEST_DIRS"
+    header_lines = []
+    test_dir_lines = []
+    for line in test_dirs_fn.read_text(encoding="utf8").split("\n"):
+        if not line.strip():
+            pass
+        elif line.startswith("#"):
+            header_lines.append(line)
+        else:
+            test_dir_lines.append(line)
+
+    def sort_key(line: str) -> float:
+        return timings.get(line.split()[0], float("inf"))
+
+    test_dir_lines.sort(key=sort_key, reverse=True)
+    output = "\n".join(header_lines + test_dir_lines) + "\n"
+    test_dirs_fn.write_text(output, encoding="utf8")
+
+    print(f"Updated {test_dirs_fn}")
+
+
+# ======================================================================================
+if __name__ == "__main__":
+    main()
+
+# EOF