Override fixes and general updates (#129)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Kalen Michael <kalenmike@gmail.com>

ultralytics/yolo/engine/trainer.py

@@ -107,6 +107,8 @@ class BaseTrainer:
         self.device = utils.torch_utils.select_device(self.args.device, self.batch_size)
         self.amp = self.device.type != 'cpu'
         self.scaler = amp.GradScaler(enabled=self.amp)
+        if self.device.type == 'cpu':
+            self.args.workers = 0  # faster CPU training as time dominated by inference, not dataloading
 
         # Model and Dataloaders.
         self.model = self.args.model