diff --git a/mainscripts/Merger.py b/mainscripts/Merger.py
index 1739c9f..fba37f1 100644
--- a/mainscripts/Merger.py
+++ b/mainscripts/Merger.py
@@ -1,4 +1,5 @@
 import math
+import multiprocessing
 import traceback
 from pathlib import Path
 
@@ -13,7 +14,8 @@ from core.joblib import MPClassFuncOnDemand, MPFunc
 from core.leras import nn
 from DFLIMG import DFLIMG
 from facelib import FaceEnhancer, FaceType, LandmarksProcessor, XSegNet
-from merger import FrameInfo, MergerConfig, InteractiveMergerSubprocessor
+from merger import FrameInfo, InteractiveMergerSubprocessor, MergerConfig
+
 
 def main (model_class_name=None,
           saved_models_path=None,
@@ -70,6 +72,9 @@ def main (model_class_name=None,
 
         if not is_interactive:
             cfg.ask_settings()
+            
+        subprocess_count = io.input_int("Number of workers?", max(8, multiprocessing.cpu_count()), 
+                                        valid_range=[1, multiprocessing.cpu_count()], help_message="Specify the number of threads to process. A low value may affect performance. A high value may result in memory error. The value may not be greater than CPU cores." )
 
         input_path_image_paths = pathex.get_image_paths(input_path)
 
@@ -199,7 +204,8 @@ def main (model_class_name=None,
                             frames_root_path       = input_path,
                             output_path            = output_path,
                             output_mask_path       = output_mask_path,
-                            model_iter             = model.get_iter()
+                            model_iter             = model.get_iter(),
+                            subprocess_count       = subprocess_count,
                         ).run()
 
         model.finalize()
diff --git a/merger/InteractiveMergerSubprocessor.py b/merger/InteractiveMergerSubprocessor.py
index 47c8a38..58db0c1 100644
--- a/merger/InteractiveMergerSubprocessor.py
+++ b/merger/InteractiveMergerSubprocessor.py
@@ -140,7 +140,7 @@ class InteractiveMergerSubprocessor(Subprocessor):
 
 
     #override
-    def __init__(self, is_interactive, merger_session_filepath, predictor_func, predictor_input_shape, face_enhancer_func, xseg_256_extract_func, merger_config, frames, frames_root_path, output_path, output_mask_path, model_iter):
+    def __init__(self, is_interactive, merger_session_filepath, predictor_func, predictor_input_shape, face_enhancer_func, xseg_256_extract_func, merger_config, frames, frames_root_path, output_path, output_mask_path, model_iter, subprocess_count=4):
         if len (frames) == 0:
             raise ValueError ("len (frames) == 0")
 
@@ -161,7 +161,7 @@ class InteractiveMergerSubprocessor(Subprocessor):
         self.output_mask_path = output_mask_path
         self.model_iter = model_iter
 
-        self.prefetch_frame_count = self.process_count = multiprocessing.cpu_count()
+        self.prefetch_frame_count = self.process_count = subprocess_count
 
         session_data = None
         if self.is_interactive and self.merger_session_filepath.exists():