diff --git a/roop/core.py b/roop/core.py
index b2b6497..ad0c2f4 100755
--- a/roop/core.py
+++ b/roop/core.py
@@ -2,24 +2,27 @@
 
 import os
 import sys
+# single thread doubles performance of gpu-mode - needs to be set before torch import
+if any(arg.startswith('--gpu-vendor=') for arg in sys.argv):
+    os.environ['OMP_NUM_THREADS'] = '1'
 import platform
 import signal
 import shutil
-import psutil
 import glob
 import argparse
 import torch
 from pathlib import Path
-import multiprocessing as mp
 from opennsfw2 import predict_video_frames, predict_image
 import cv2
 
 import roop.globals
-from roop.swapper import process_video, process_img, process_faces, process_frames
+from roop.swapper import process_video, process_img, process_faces
 from roop.utils import is_img, detect_fps, set_fps, create_video, add_audio, extract_frames, rreplace
 from roop.analyser import get_face_single
 import roop.ui as ui
 
+if 'ROCMExecutionProvider' in roop.globals.providers:
+    del torch
 
 signal.signal(signal.SIGINT, lambda signal_number, frame: quit())
 parser = argparse.ArgumentParser()
@@ -30,7 +33,7 @@ parser.add_argument('--keep-fps', help='maintain original fps', dest='keep_fps',
 parser.add_argument('--keep-frames', help='keep frames directory', dest='keep_frames', action='store_true', default=False)
 parser.add_argument('--all-faces', help='swap all faces in frame', dest='all_faces', action='store_true', default=False)
 parser.add_argument('--max-memory', help='maximum amount of RAM in GB to be used', dest='max_memory', type=int)
-parser.add_argument('--max-cores', help='number of cores to use at max', dest='max_cores', type=int)
+parser.add_argument('--cpu-threads', help='number of threads to be use for CPU mode', dest='cpu_threads', type=int)
 parser.add_argument('--gpu-threads', help='number of threads to be use for GPU mode', dest='gpu_threads', type=int)
 parser.add_argument('--gpu-vendor', help='choice your gpu vendor', dest='gpu_vendor', choices=['apple', 'amd', 'intel', 'nvidia'])
 
@@ -41,18 +44,14 @@ for name, value in vars(parser.parse_args()).items():
 if 'all_faces' in args:
     roop.globals.all_faces = True
 
-if args['max_cores']:
-    roop.globals.max_cores = args['max_cores']
-else:
-    roop.globals.max_cores = psutil.cpu_count() - 1
+if 'cpu_threads' in args and args['cpu_threads']:
+    roop.globals.cpu_threads = args['cpu_threads']
 
-if args['gpu_threads']:
+if 'gpu_threads' in args and args['gpu_threads']:
     roop.globals.gpu_threads = args['gpu_threads']
 
-if args['gpu_vendor']:
+if 'gpu_vendor' in args and args['gpu_vendor']:
     roop.globals.gpu_vendor = args['gpu_vendor']
-else:
-    roop.globals.providers = ['CPUExecutionProvider']
 
 sep = "/"
 if os.name == "nt":
@@ -138,20 +137,7 @@ def status(string):
         ui.update_status_label(value)
 
 
-def process_video_multi_cores(source_img, frame_paths):
-    n = len(frame_paths) // roop.globals.max_cores
-    if n > 2:
-        processes = []
-        for i in range(0, len(frame_paths), n):
-            p = pool.apply_async(process_frames, args=(source_img, frame_paths[i:i+n],))
-            processes.append(p)
-        for p in processes:
-            p.get()
-        pool.close()
-        pool.join()
-
-
-def start(preview_callback=None):
+def start(preview_callback = None):
     if not args['source_img'] or not os.path.isfile(args['source_img']):
         print("\n[WARNING] Please select an image containing a face.")
         return
@@ -177,7 +163,7 @@ def start(preview_callback=None):
         quit()
     video_name_full = target_path.split("/")[-1]
     video_name = os.path.splitext(video_name_full)[0]
-    output_dir = os.path.dirname(target_path) + "/" + video_name if os.path.dirname(target_path) else video_name 
+    output_dir = os.path.dirname(target_path) + "/" + video_name
     Path(output_dir).mkdir(exist_ok=True)
     status("detecting video's FPS...")
     fps, exact_fps = detect_fps(target_path)
@@ -194,12 +180,7 @@ def start(preview_callback=None):
         key=lambda x: int(x.split(sep)[-1].replace(".png", ""))
     ))
     status("swapping in progress...")
-    if sys.platform != 'darwin' and not args['gpu_vendor']:
-        global pool
-        pool = mp.Pool(roop.globals.max_cores)
-        process_video_multi_cores(args['source_img'], args['frame_paths'])
-    else:
-        process_video(args['source_img'], args["frame_paths"], preview_callback)
+    process_video(args['source_img'], args["frame_paths"], preview_callback)
     status("creating video...")
     create_video(video_name, exact_fps, output_dir)
     status("adding audio...")