diff --git a/cellmap_flow/blockwise/blockwise_processor.py b/cellmap_flow/blockwise/blockwise_processor.py
index 87b6fd6..f1c6dc4 100644
--- a/cellmap_flow/blockwise/blockwise_processor.py
+++ b/cellmap_flow/blockwise/blockwise_processor.py
@@ -152,13 +152,15 @@ def process_fn(self, block):
             print(f"empty write roi: {write_roi}")
             return
 
+        # Check if block is already processed before expensive inference computation
+        fill_value = getattr(self.output_arrays[0], 'fill_value', self.dtype(0))
+        if not (self.output_arrays[0][write_roi] == fill_value).all():
+            return
+
         chunk_data = self.inferencer.process_chunk(self.idi_raw, block.write_roi)
 
         chunk_data = chunk_data.astype(self.dtype)
 
-        if self.output_arrays[0][block.write_roi].any():
-            return
-
         for i, array in enumerate(self.output_arrays):
 
             if chunk_data.shape == 3:
@@ -217,8 +219,8 @@ def run(self):
             ),
             read_write_conflict=True,
             fit="overhang",
-            max_retries=0,
-            timeout=None,
+            max_retries=2,
+            timeout=1800,
             num_workers=self.workers,
         )