Yes i understand that it needs 10-15 seconds on bettwen frames, but then each pure render is 30% slower than viewport render.

I noticed, that when i render to disk or mplay my GPU usage is strange. As the graph says, it is saw type. (but still my PC is almost frozen at that time). While viewport rendering GPU usage is clean 100%. Maybe GTX 970 is a very old and that is a problem?

Thank you!

I feel like I have a similar issue (rtx 3080), but to me it seems like that might be loading time (dicing, displacing etc) because the actual render itself goes quick when it eventually starts.

If anyone wanders, the problem was due to my old GPU