Update benchmarks/benchmark_throughput.py

Co-authored-by: Simon Mo <simon.mo@hey.com>

Author: kartikx

benchmarks/benchmark_throughput.py

@@ -523,7 +523,7 @@ def validate_args(args):
     # --data-parallel is not supported currently.
     # https://github.com/vllm-project/vllm/issues/16222
     if args.data_parallel_size > 1:
-        raise ValueError("Data parallel is not supported currently.")
+        raise ValueError("Data parallel is not supported in offline benchmark, please use benchmark serving instead")
 
 if __name__ == "__main__":
     parser = FlexibleArgumentParser(description="Benchmark the throughput.")