This is a good question, but I'm not sure it's answerable. (Or, if it is answerable, you'll get answers from controlled experiments that will be useless to compare to real-world usage.)
I know from experience that my gas-powered saw will run for about 30-40 minutes on a tank of gas when I'm bucking logs for firewood. That's running at more or less full throttle for a significant portion of that time -- I move from cut to cut rapidly because the logs are mostly ready to cut.
But it's hard to know how much wood (i.e. measured in cords) I'm going to actually cut in that time, because the mix of logs (species, age/seasoning, size) isn't uniform and the chain dulls over a couple-hour cutting session. Even on a single cut, I know that the saw will zip through a 4" hemlock that's been down a year but will take forever to work both sides of an ancient 30+" maple that's full of knots.
Finally, performance of the saw will depend on how well you maintain it. Again from experience I know that if I haven't done my job properly (sharpening, cleaning, etc) then it doesn't run as well or cut as well. I occasionally think, "Oh just one more tank of gas", and regret it because it doesn't cut for beans and my time would have been better spent in the garage sharpening and/or cleaning the machine so it runs smoothly & cuts fast.