Standing the material up verses laying it down:
The thinner cross section will cut faster, but problems that come with this are:
The taller the cut, the more chance of taper.
The taller the cut, the wider the adjusting support must be open at the top and too wide at the bottom.
The taller the cut, the feed rate drastically changes from top to bottom due to frame weight shift.
Laying the stock down still includes other issues.
More teeth in the material, the less bite it can get, forcing you to slow the feed rate to something the blade can handle. Sometimes a test in patience with a bad combination of material and blade tooth count or sharpness. But hey, if all is well, you might gain a straighter cut....
Was there ever a line in Star Trek where someone said. "Damnit Jim, It's a saw, not a laser" ?
DC