Single large vs triple small L tube stove

[nixsee]

I'd like to boil a massive (100L - half steel drum) pot.

I have a 200L steel drum which is 34" high and is 22.5" inner diameter. I'm considering two options:

1. Single large stove - allowing for some insulation (I'm using pumice stone) in the bottom, 34" would allow maybe a 10-12" diameter tube. But this isn't a particularly useful stove height with another 17" pot on top.

2. Cut the drum in half and have 3 smaller stoves within the 17" half drum (and another 2 or 3 within the other half). With bottom insulation taking a few inches, the 3 stoves could probably be 5" diameter.

Side note: is 3x height to diameter necessary? What about 2.5x?

Assuming adequate insulation, putting aside ergonomics and the fact that there is a larger cross sectional area in the single large stove, are larger or smaller stoves more efficient?

A further question:
Let's say the 5" were 5x5 square combustion chambers. You could put them side by side, or even have a shared inner wall. What would happen if you then got rid of the inner wall and had a 10x5 chamber with the same 15" riser? Does a stove suffer the further you get from square/circular?

[pigbuttons]

Multiple stoves almost never works, especially if you want them to share chimneys or anything for that matter. One big one is almost always preferred. I'm having a hard time following exactly how you plan to build your cook stove, but if your main goal is to boil water, understand that it takes a huge amount of energy to raise that much water to boiling temps. So all things considered, bigger is better.

What will you be cooking? heating? What is the environment where the stove will go? How fast must it heat the liquid? You mention pumice as insulation but not what the firebox, riser, and burn tunnel will be made of? Indoors or outdoors?