I didn't think I had to lay it ALL out to get the answer to the question I was asking.
I just asked what was the lowest power-absorbing kind of drill bit to use to drill numerous holes in SPF floor joists. I guess I gave TOO MUCH information in my request, which sent everybody off in all sorts of directions OTHER than the power requirements of different drilling methods.
Then I got stuck explaining why the answers I was getting were not the answer to the question I asked.
The answer, from trying it and other observations - A) -The spade bit breaks through unpredictable and may jam, causing high torque to be transmitted through the drive (it took the gearcase off a brand new PorterCable hanner drill, running in straight drilling mode and low gear with ONE catch)
B) - an auger bit in the size I required was not readily available to test
C) a 1/3.4" Forstner bit with 7/16" hex drive was available to be tried, and it had no break-through issues, even when not drilling square because of it's self guiding and basically 360 degree cutting action. . It exhibited very low driving torque requirements as detected at the drill-motor - and did the job just fine.
It did the job on the end of a series of 1.2 inch water pipes threaded together to go in 12 feet.