I've got a tree in the back I want to take down. Roughly 13" or so diameter, but forks at ground level, so basically two trunks, I'll knock it down when the weather here straightens out. I think it's an ash, but that's a guess. It should be a good test tree. I'll take it down and see what it feels like. Maybe grab some video on a few cuts.Put a log horizontal, square up the end to be like a cant, then make 3 cuts down up down note the time. Change to various other chains and do similar. If you do not have a timing system a video generally will have a counter.
Then find a hardwood tree and cut off branches in a manner in line with the trunk like to make the log round. If I recall this is where quite a difference seems to exist but isn't something that can be timed and compared easily if at all.