diff --git a/.github/actions/environment/unit-mpi/action.yml b/.github/actions/environment/unit-mpi/action.yml
deleted file mode 100644
index a0263bfbe..000000000
--- a/.github/actions/environment/unit-mpi/action.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-name: Set environment variables for mpi unit tests
-
-description: 
-
-inputs:
-  n-procs:
-    default: 2
-
-runs:
-  using: composite
-  steps:
-    - name: set and export variables
-      shell: bash
-      run: |
-        TESTMON_KEY="testmon-unit-mpi"
-        RUN_MAXWELL="mpirun -n 1 pytest -m single --testmon-forceselect -v --with-mpi --model-name Maxwell"
-        PYTEST_CMD="mpirun -n ${{ inputs.n-procs }} pytest -v --testmon --with-mpi"
-        echo "TESTMON_KEY=${TESTMON_KEY}" >> $GITHUB_ENV
-        echo "RUN_MAXWELL=${RUN_MAXWELL}" >> $GITHUB_ENV
-        echo "PYTEST_CMD=${PYTEST_CMD}" >> $GITHUB_ENV
\ No newline at end of file
diff --git a/.github/actions/environment/unit-serial/action.yml b/.github/actions/environment/unit-serial/action.yml
deleted file mode 100644
index 07d01cb9d..000000000
--- a/.github/actions/environment/unit-serial/action.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-name: Set environment variables for serial unit tests
-
-description: 
-
-runs:
-  using: composite
-  steps:
-    - name: set and export variables
-      shell: bash
-      run: |
-        TESTMON_KEY="testmon-unit"
-        UNINSTALL_MPI="pip uninstall -y mpi4py"
-        PYTEST_CMD="pytest -v --testmon"
-        echo "TESTMON_KEY=${TESTMON_KEY}" >> $GITHUB_ENV
-        echo "UNINSTALL_MPI=${UNINSTALL_MPI}" >> $GITHUB_ENV
-        echo "PYTEST_CMD=${PYTEST_CMD}" >> $GITHUB_ENV
\ No newline at end of file
diff --git a/.github/actions/tests/unit/action.yml b/.github/actions/tests/unit/action.yml
deleted file mode 100644
index 1e1ce476a..000000000
--- a/.github/actions/tests/unit/action.yml
+++ /dev/null
@@ -1,45 +0,0 @@
-name: "Run unit tests"
-
-description: 
-
-inputs:
-  struphy-path:
-    required: true
-  env-name:
-    default: ""
-
-runs:
-  using: composite
-  steps:
-    - name: Run unit tests (serial) in container
-      shell: bash
-      env:
-        TESTMON_DATAFILE: ${{ github.workspace }}/.testmondata-unit
-        TEST_FILES: "bsplines/tests/ \
-                    console/tests/ \
-                    feec/tests/ \
-                    fields_background/tests/ \
-                    geometry/tests/ \
-                    initial/tests/ \
-                    kinetic_background/tests/ \
-                    linear_algebra/tests/ \
-                    ode/tests/ \
-                    pic/tests/ \
-                    polar/tests/ \
-                    post_processing/tests/ \
-                    propagators/tests/"
-      run: |
-        set +e
-        source ${{ inputs.env-name }}/bin/activate || true
-        set -e
-        pip show struphy
-        struphy compile --status
-        cd ${{ inputs.struphy-path }}
-        pwd
-        echo "Running $RUN_MAXWELL"
-        $RUN_MAXWELL
-        echo "Running $UNINSTALL_MPI"
-        $UNINSTALL_MPI
-        git status || true
-        echo "Running $PYTEST_CMD $TEST_FILES"
-        $PYTEST_CMD $TEST_FILES
diff --git a/.github/workflows/reusable-scheduled.yml b/.github/workflows/reusable-scheduled.yml
index 8baef906c..fa12f281a 100644
--- a/.github/workflows/reusable-scheduled.yml
+++ b/.github/workflows/reusable-scheduled.yml
@@ -9,6 +9,7 @@ on:
 
 jobs:
   test:
+    name: ${{ matrix.test-type }} (${{ matrix.compile-language }}, ${{ matrix.shard }})
     runs-on: ${{ inputs.os }}
     env:
       OMPI_MCA_rmaps_base_oversubscribe: 1 # Linux
@@ -19,6 +20,20 @@ jobs:
         python-version: ["3.12"]
         compile-language: ["fortran", "c"]
         test-type: ["unit", "model", "verification"] #"quickstart", "tutorials"]
+        shard: ["shard-1", "shard-2", "shard-3", "shard-4"]
+        exclude:
+          - test-type: model
+            shard: shard-2
+          - test-type: model
+            shard: shard-3
+          - test-type: model
+            shard: shard-4
+          - test-type: verification
+            shard: shard-2
+          - test-type: verification
+            shard: shard-3
+          - test-type: verification
+            shard: shard-4
 
     steps:
       # Checkout the repository
@@ -74,22 +89,60 @@ jobs:
           language: ${{ matrix.compile-language }}
 
       - name: Set environment for mpi run
-        uses: ./.github/actions/environment/unit-mpi
+        run: |
+          {
+            echo 'TESTMON_KEY=testmon-unit-mpi'
+            echo 'RUN_MAXWELL=mpirun -n 1 pytest -m single --testmon-forceselect -v --with-mpi --model-name Maxwell'
+            echo 'UNINSTALL_MPI='
+            echo 'PYTEST_CMD=mpirun -n 2 pytest -v --testmon --with-mpi'
+          } >> "$GITHUB_ENV"
 
       - name: Run unit tests with MPI
         if: matrix.test-type == 'unit'
-        uses: ./.github/actions/tests/unit
-        with:
-          struphy-path: ${{ env.STRUPHY_PATH }}
+        env:
+          TESTMON_DATAFILE: ${{ github.workspace }}/.testmondata-unit-${{ matrix.shard }}
+        run: |
+          case "${{ matrix.shard }}" in
+            shard-1)
+              TEST_FILES="bsplines/tests/ console/tests/ fields_background/tests/ geometry/tests/ initial/tests/ kinetic_background/tests/ linear_algebra/tests/"
+              ;;
+            shard-2)
+              TEST_FILES="propagators/tests/ ode/tests/ polar/tests/ post_processing/tests/"
+              ;;
+            shard-3)
+              TEST_FILES="feec/tests/"
+              ;;
+            shard-4)
+              TEST_FILES="pic/tests/"
+              ;;
+            *)
+              echo "Unknown test shard: ${{ matrix.shard }}" >&2
+              exit 1
+              ;;
+          esac
+          set +e
+          source /bin/activate || true
+          set -e
+          pip show struphy
+          struphy compile --status
+          cd ${{ env.STRUPHY_PATH }}
+          pwd
+          echo "Running $RUN_MAXWELL"
+          $RUN_MAXWELL
+          echo "Running $UNINSTALL_MPI"
+          $UNINSTALL_MPI
+          git status || true
+          echo "Running $PYTEST_CMD $TEST_FILES"
+          $PYTEST_CMD $TEST_FILES
 
       - name: Run model tests with MPI
-        if: matrix.test-type == 'model'
+        if: matrix.test-type == 'model' && matrix.shard == 'shard-1'
         shell: bash
         run: |
           mpirun -oversubscribe -n 2 pytest -x -m models --with-mpi $STRUPHY_PATH/models/tests/default_params/
 
       - name: Run verification tests with MPI
-        if: matrix.test-type == 'verification'
+        if: matrix.test-type == 'verification' && matrix.shard == 'shard-1'
         shell: bash
         run: |
           mpirun --oversubscribe -n 2 pytest -x --with-mpi $STRUPHY_PATH/models/tests/verification/
diff --git a/.github/workflows/reusable-unit-testing.yml b/.github/workflows/reusable-unit-testing.yml
index d2dca306d..6fbf21f07 100644
--- a/.github/workflows/reusable-unit-testing.yml
+++ b/.github/workflows/reusable-unit-testing.yml
@@ -21,8 +21,29 @@ permissions:
   contents: read
 
 jobs:
+  preflight:
+    runs-on: ${{ inputs.os }}
+    steps:
+      - name: Check memory
+        run: |
+          free -h
+          grep -E 'MemTotal|MemAvailable|SwapTotal|SwapFree' /proc/meminfo
+
   unit-tests-in-container-with-struphy:
+    name: Unit tests (${{ matrix.shard }})
     runs-on: ${{ inputs.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - shard: shard-1
+            test_files: bsplines/tests/ console/tests/ fields_background/tests/ geometry/tests/ initial/tests/ kinetic_background/tests/ linear_algebra/tests/
+          - shard: shard-2
+            test_files: propagators/tests/ ode/tests/ polar/tests/ post_processing/tests/
+          - shard: shard-3
+            test_files: feec/tests/
+          - shard: shard-4
+            test_files: pic/tests/  
 
     container:
       image: ghcr.io/struphy-hub/struphy/ubuntu-with-struphy:latest
@@ -34,6 +55,11 @@ jobs:
       - name: Check for dockerenv file
         run: (ls /.dockerenv && echo Found dockerenv) || (echo No dockerenv)
 
+      - name: Memory inside container
+        run: |
+          free -h
+          grep -E 'MemTotal|MemAvailable|SwapTotal|SwapFree' /proc/meminfo
+
       - name: Checkout repo
         uses: actions/checkout@v4
         with:
@@ -42,11 +68,23 @@ jobs:
 
       - name: Set environment for serial run
         if: inputs.n-procs == 1
-        uses: ./.github/actions/environment/unit-serial
+        run: |
+          {
+            echo 'TESTMON_KEY=testmon-unit'
+            echo 'RUN_MAXWELL='
+            echo 'UNINSTALL_MPI=pip uninstall -y mpi4py'
+            echo 'PYTEST_CMD=pytest -v --testmon'
+          } >> "$GITHUB_ENV"
 
       - name: Set environment for mpi run
         if: inputs.n-procs > 1
-        uses: ./.github/actions/environment/unit-mpi
+        run: |
+          {
+            echo 'TESTMON_KEY=testmon-unit-mpi'
+            echo 'RUN_MAXWELL=mpirun -n 1 pytest -m single --testmon-forceselect -v --with-mpi --model-name Maxwell'
+            echo 'UNINSTALL_MPI='
+            echo 'PYTEST_CMD=mpirun -n ${{ inputs.n-procs }} pytest -v --testmon --with-mpi'
+          } >> "$GITHUB_ENV"
 
       - name: Check .testmondata 1
         run: |
@@ -56,12 +94,12 @@ jobs:
         uses: actions/cache@v4
         with:
           path: |
-            .testmondata-unit
-          key: ${{ env.TESTMON_KEY }}-${{ github.ref_name }}-${{ github.event.number }}-${{ github.run_number }}
+            .testmondata-unit-${{ matrix.shard }}
+          key: ${{ env.TESTMON_KEY }}-${{ matrix.shard }}-${{ github.ref_name }}-${{ github.event.number }}-${{ github.run_number }}
           restore-keys: |
-            ${{ env.TESTMON_KEY }}-${{ github.ref_name }}-${{ github.event.number }}-
-            ${{ env.TESTMON_KEY }}-${{ github.ref_name }}
-            ${{ env.TESTMON_KEY }}-devel
+            ${{ env.TESTMON_KEY }}-${{ matrix.shard }}-${{ github.ref_name }}-${{ github.event.number }}-
+            ${{ env.TESTMON_KEY }}-${{ matrix.shard }}-${{ github.ref_name }}
+            ${{ env.TESTMON_KEY }}-${{ matrix.shard }}-devel
             ${{ env.TESTMON_KEY }}-
 
       - name: Check .testmondata 2
@@ -88,7 +126,21 @@ jobs:
           env-name: /struphy_fortran_/env_fortran_
 
       - name: Run unit tests
-        uses: ./.github/actions/tests/unit
-        with:
-          struphy-path: ${{ env.STRUPHY_PATH }}
-          env-name: /struphy_fortran_/env_fortran_
\ No newline at end of file
+        env:
+          TESTMON_DATAFILE: ${{ github.workspace }}/.testmondata-unit-${{ matrix.shard }}
+          TEST_FILES: ${{ matrix.test_files }}
+        run: |
+          set +e
+          source /struphy_fortran_/env_fortran_/bin/activate || true
+          set -e
+          pip show struphy
+          struphy compile --status
+          cd ${{ env.STRUPHY_PATH }}
+          pwd
+          echo "Running $RUN_MAXWELL"
+          $RUN_MAXWELL
+          echo "Running $UNINSTALL_MPI"
+          $UNINSTALL_MPI
+          git status || true
+          echo "Running $PYTEST_CMD $TEST_FILES"
+          $PYTEST_CMD $TEST_FILES
\ No newline at end of file
diff --git a/docker/ubuntu-latest-with-struphy.dockerfile b/docker/ubuntu-latest-with-struphy.dockerfile
index 6a95d3a9c..9b3381414 100644
--- a/docker/ubuntu-latest-with-struphy.dockerfile
+++ b/docker/ubuntu-latest-with-struphy.dockerfile
@@ -12,6 +12,7 @@
 FROM ubuntu:latest
 
 ARG DEBIAN_FRONTEND=noninteractive
+ARG PYTHON_VERSION=3.13
 
 # install linux packages
 RUN apt update -y && apt clean \
@@ -19,10 +20,11 @@ RUN apt update -y && apt clean \
     && add-apt-repository -y ppa:deadsnakes/ppa \
     && apt update -y 
 
-RUN apt install -y python3 \
-    && apt install -y python3-dev \
-    && apt install -y python3-pip \
-    && apt install -y python3-venv 
+RUN apt install -y python${PYTHON_VERSION} \
+    && apt install -y python${PYTHON_VERSION}-dev \
+    && apt install -y python${PYTHON_VERSION}-venv \
+    && update-alternatives --install /usr/bin/python3 python3 /usr/bin/python${PYTHON_VERSION} 1 \
+    && update-alternatives --set python3 /usr/bin/python${PYTHON_VERSION}
 
 RUN apt install -y gfortran gcc \
     && apt install -y liblapack-dev libblas-dev 
@@ -44,32 +46,32 @@ RUN apt install -y g++ liblapack3 cmake cmake-curses-gui zlib1g-dev libnetcdf-de
     && export CXX=`which g++`  
 
 # install three versions of struphy
-RUN git clone https://github.com/struphy-hub/struphy.git struphy_c_ \
-    && cd struphy_c_ \
-    && python3 -m venv env_c_ \
-    && . env_c_/bin/activate \
-    && pip install -U pip \
-    && pip install -e .[phys,mpi,doc] --no-cache-dir \
-    && struphy compile \
-    && deactivate
+# RUN git clone https://github.com/struphy-hub/struphy.git struphy_c_ \
+#     && cd struphy_c_ \
+#     && python${PYTHON_VERSION} -m venv env_c_ \
+#     && . env_c_/bin/activate \
+#     && pip install -U pip \
+#     && pip install -e .[phys,mpi,doc] --no-cache-dir \
+#     && struphy compile \
+#     && deactivate
     
 RUN git clone https://github.com/struphy-hub/struphy.git struphy_fortran_\
     && cd struphy_fortran_ \
-    && python3 -m venv env_fortran_ \
+    && python${PYTHON_VERSION} -m venv env_fortran_ \
     && . env_fortran_/bin/activate \
     && pip install -U pip \
     && pip install -e .[phys,mpi,doc] --no-cache-dir \
     && struphy compile --language fortran -y \
     && deactivate 
 
-RUN git clone https://github.com/struphy-hub/struphy.git struphy_fortran_--omp-pic\
-    && cd struphy_fortran_--omp-pic \
-    && python3 -m venv env_fortran_--omp-pic \
-    && . env_fortran_--omp-pic/bin/activate \
-    && pip install -U pip \
-    && pip install -e .[phys,mpi,doc] --no-cache-dir \
-    && struphy compile --language fortran --omp-pic -y \
-    && deactivate 
+# RUN git clone https://github.com/struphy-hub/struphy.git struphy_fortran_--omp-pic\
+#     && cd struphy_fortran_--omp-pic \
+#     && python${PYTHON_VERSION} -m venv env_fortran_--omp-pic \
+#     && . env_fortran_--omp-pic/bin/activate \
+#     && pip install -U pip \
+#     && pip install -e .[phys,mpi,doc] --no-cache-dir \
+#     && struphy compile --language fortran --omp-pic -y \
+#     && deactivate 
 
 # allow mpirun as root
 ENV OMPI_ALLOW_RUN_AS_ROOT=1
diff --git a/pyproject.toml b/pyproject.toml
index 3a600a09b..ca2288feb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,7 +37,7 @@ dependencies = [
     "ipywidgets<=8.1.8",
     "plotly<=6.7.0",
     "pyvista<=0.48.0",
-    "trame<=3.12.0",
+    "trame<=3.13.0",
     "trame-vtk<=2.11.8",
     "trame-vuetify<=3.2.2",
     "nest_asyncio2<=1.7.2",
diff --git a/src/struphy/pic/tests/test_sph.py b/src/struphy/pic/tests/test_sph.py
index bdfdd093c..4a1ea8cbd 100644
--- a/src/struphy/pic/tests/test_sph.py
+++ b/src/struphy/pic/tests/test_sph.py
@@ -60,6 +60,7 @@ def test_sph_evaluation_1d(
         if derivative == 0:
             ppb = 1000
         else:
+            # return  # skip non-tesselation test for derivative in 1D
             ppb = 20000
         loading_params = LoadingParameters(ppb=ppb, seed=223)
 
@@ -543,6 +544,7 @@ def test_evaluation_SPH_h_convergence_1d(boxes_per_dim, bc_x, eval_pts, tesselat
         ppb = 160
         loading_params = LoadingParameters(ppb=ppb, loading="tesselation")
     else:
+        # return  # skip non-tesselation test for h-convergence in 1D
         Np = 160000
         ppb = None
         loading_params = LoadingParameters(Np=Np, ppb=ppb, seed=1607)
@@ -660,6 +662,7 @@ def test_evaluation_mc_Np_and_h_convergence_1d(boxes_per_dim, bc_x, eval_pts, te
         ppbs = [4, 8, 16, 32, 64]
         Nps = [None] * len(ppbs)
     else:
+        # return  # skip non-tesselation test for convergence in 1D
         Nps = [(2**k) * 10**3 for k in range(-2, 9)]
         ppbs = [None] * len(Nps)
 
@@ -1968,6 +1971,7 @@ def u_xyz(x, y, z):
     #     direction="x",
     #     show_plot=True,
     # )
-    test_sph_velocity_evaluation_2d(
-        (12, 12, 1), "gaussian_2d", 1, "periodic", "periodic", 11, tesselation=False, show_plot=True
-    )
+    # test_sph_velocity_evaluation_2d(
+    #     (12, 12, 1), "gaussian_2d", 1, "periodic", "periodic", 11, tesselation=False, show_plot=True
+    # )
+    test_sph_evaluation_1d((24, 1, 1), "trigonometric_1d", 0, "periodic", 11, tesselation=False, show_plot=True)