Default AutoBatch 0.8 fraction (#9212)

utils/autobatch.py

@@ -18,7 +18,7 @@ def check_train_batch_size(model, imgsz=640, amp=True):
         return autobatch(deepcopy(model).train(), imgsz)  # compute optimal batch size
 
 
-def autobatch(model, imgsz=640, fraction=0.9, batch_size=16):
+def autobatch(model, imgsz=640, fraction=0.8, batch_size=16):
     # Automatically estimate best batch size to use `fraction` of available CUDA memory
     # Usage:
     #     import torch