Are you splitting the wood? Cutting sections? Are you hiking in with your tools?

I would not recommend the wire saw for a large quantity of cutting. If weight is not a problem, an axe would be fastest. If the weight is an issue, a hatchet or folding saw would work. The survival chain saws work well if you can hold the wood still, better for large limbs and such if you are alone. This one works very well Unbelievable Chain Saw .

Fox Knives Roman Style Hunter's Axe is the hatchet I carry. Very light, aggressive cutter, easy to keep sharp, comfortable handle.