diff --git a/examples/fromfile_irreg/fromfile_irreg_inputfiles.py b/examples/fromfile_irreg/fromfile_irreg_inputfiles.py
index 8d09ccbd..385eb97a 100644
--- a/examples/fromfile_irreg/fromfile_irreg_inputfiles.py
+++ b/examples/fromfile_irreg/fromfile_irreg_inputfiles.py
@@ -55,10 +55,12 @@ def main(path2CLEO, path2build, configfile, gridfile, initSDsfile, thermofile):
     isfigures = [True, True]
     savefigpath = path2build + "/bin/"  # directory for saving figures
 
-    ### --- settings for 2-D gridbox boundaries --- ###
-    zgrid = [0, 1500, 60]  # evenly spaced zhalf coords [zmin, zmax, zdelta] [m]
-    xgrid = [0, 1500, 50]  # evenly spaced xhalf coords [m]
-    ygrid = np.array([0, 100, 200, 300])  # array of yhalf coords [m]
+    ### --- settings for 3-D irregular gridbox boundaries --- ###
+    zgrid = np.array([0, 20, 30, 45, 60, 80, 90, 120, 140, 180, 360, 500, 1000, 1500])
+    xgrid = np.array(
+        [0, 33, 205, 440, 650, 915, 1033, 1100, 1300, 1450, 1500]
+    )  # evenly spaced xhalf coords [m]
+    ygrid = np.array([0, 10, 75, 100, 150, 200, 300])  # array of yhalf coords [m]
 
     ### --- settings for initial superdroplets --- ###
     # settings for initial superdroplet coordinates
diff --git a/examples/fromfile_irreg/src/config/fromfile_irreg_config.yaml b/examples/fromfile_irreg/src/config/fromfile_irreg_config.yaml
index 8911fea3..ea29a6f1 100644
--- a/examples/fromfile_irreg/src/config/fromfile_irreg_config.yaml
+++ b/examples/fromfile_irreg/src/config/fromfile_irreg_config.yaml
@@ -25,8 +25,8 @@
 ### SDM Runtime Parameters ###
 domain:
   nspacedims : 3                                          # no. of spatial dimensions to model
-  ngbxs : 2250                                            # total number of Gbxs
-  maxnsupers: 2880                                        # maximum number of SDs
+  ngbxs : 780                                             # total number of Gbxs
+  maxnsupers: 1440                                        # maximum number of SDs
 
 timesteps:
   CONDTSTEP : 2                                           # time between SD condensation [s]
@@ -34,7 +34,7 @@ timesteps:
   MOTIONTSTEP : 3                                         # time between SDM motion [s]
   COUPLTSTEP : 1800                                       # time between dynamic couplings [s]
   OBSTSTEP : 1800                                         # time between SDM observations [s]
-  T_END : 7200                                            # time span of integration from 0s to T_END [s]
+  T_END : 10800                                            # time span of integration from 0s to T_END [s]
 
 ### Initialisation Parameters ###
 inputfiles: