diff --git a/bin/wfbench b/bin/wfbench
index 252b87b1..90980e46 100755
--- a/bin/wfbench
+++ b/bin/wfbench
@@ -358,7 +358,7 @@ def get_parser() -> argparse.ArgumentParser:
                                                "(e.g., --output-files {\\\"file1\\\": 1024, \\\"file2\\\": 2048}).")
     parser.add_argument("--input-files", help="Input files names as a JSON array "
                                               "(e.g., --input-files [\\\"file3\\\", \\\"file4\\\"]).")
-    parser.add_argument("--silent", action="store_true", help="Disable all log messages.")
+    parser.add_argument("--verbose", action="store_true", help="Enable all log messages.")
     parser.add_argument("--debug", action="store_true", help="Enable debug log messages.")
     parser.add_argument("--with-flowcept", action="store_true", default=False, help="Enable Flowcept monitoring.")
     parser.add_argument("--workflow_id", default=None, help="Id to group tasks in a workflow.")
@@ -387,8 +387,8 @@ def compute_num_chunks(time_limit, cpu_work, gpu_work, num_chunks):
     # Compute the (feasible number of chunks)
     min_chunk_size_time = 1 # At least 1 second per chunk, if we're doing time-based
     # TODO: Pick reasonable factors below so that a chunk takes about min_chunk_size_time sec on a reasonable machine
-    min_chunk_size_cpu_work = 3000000 * min_chunk_size_time  # 1s on my MacBook Pro
-    min_chunk_size_gpu_work = 30000000 * min_chunk_size_time # unknown.....
+    min_chunk_size_cpu_work = 2500 * min_chunk_size_time  # 1s on Henri's MacBook Pro
+    min_chunk_size_gpu_work = 2000 * min_chunk_size_time # unknown.....
 
     if time_limit:
         num_chunks = min(num_chunks, time_limit // min_chunk_size_time)
@@ -396,12 +396,18 @@ def compute_num_chunks(time_limit, cpu_work, gpu_work, num_chunks):
         if cpu_work:
             num_chunks_cpu = min(num_chunks, cpu_work // min_chunk_size_cpu_work)
         else:
-            num_chunks_cpu = 1
+            num_chunks_cpu = None
         if gpu_work:
             num_chunks_gpu = min(num_chunks, gpu_work // min_chunk_size_gpu_work)
         else:
-            num_chunks_gpu = 1
-        num_chunks = min(num_chunks_cpu, num_chunks_gpu)
+            num_chunks_gpu = None
+
+        if num_chunks_cpu is None:
+            num_chunks = num_chunks_gpu
+        elif num_chunks_gpu is None:
+            num_chunks = num_chunks_cpu
+        else:
+            num_chunks = min(num_chunks_cpu, num_chunks_gpu)
 
     num_chunks = max(num_chunks, 1)  # The above computations may say "zero"
     return num_chunks
@@ -412,7 +418,7 @@ def kill_current_handles(handles: list[ProcessHandle]):
             handle.terminate_along_with_children()
 
 
-def run(workflow_id, name, with_flowcept, silent, debug, rundir, path_lock, path_cores,
+def run(workflow_id, name, with_flowcept, verbose, debug, rundir, path_lock, path_cores,
         time_limit, cpu_work, percent_cpu, mem, gpu_work, num_chunks,
         input_files, output_files):
     """Main function."""
@@ -423,7 +429,7 @@ def run(workflow_id, name, with_flowcept, silent, debug, rundir, path_lock, path
         flowcept = None
         flowcept_task = None
 
-    if silent:
+    if verbose:
         logging.getLogger().setLevel(logging.NOTSET)
     if debug:
         logging.getLogger().setLevel(logging.DEBUG)
@@ -606,6 +612,9 @@ def main():
     if not args.time_limit and (not args.cpu_work and not args.gpu_work):
         log_error("At least one of --time-limit, --cpu-work, or --gpu-work should be provided.")
         sys.exit(1)
+    if args.time_limit and (not args.cpu_work and not args.gpu_work):
+        log_error("In addition to --time-limit, at least one of --cpu-work or --gpu-work must be provided (to specify which kind of work should be done).")
+        sys.exit(1)
 
     run(**vars(args))
     
diff --git a/wfcommons/wfbench/translator/templates/swift_t/workflow.swift b/wfcommons/wfbench/translator/templates/swift_t/workflow.swift
index 3b5c4c81..7d700ddc 100644
--- a/wfcommons/wfbench/translator/templates/swift_t/workflow.swift
+++ b/wfcommons/wfbench/translator/templates/swift_t/workflow.swift
@@ -123,7 +123,7 @@ mod.run(
     output_files=f'{{"{output_file}": {output_file_size}}}',
     input_files=str(input_file).replace("'", '"'),
     with_flowcept=bool(workflow_id),
-    silent=False,
+    verbose=False,
     debug=False,
     rundir=None,
     path_lock=None,