Oouch. I thought my rare dips of 55fps was annoying while visiting crashed scout ships, I would not play at 3-17fps as that is a slide show and not a game.
I've tolerated GA flight sims at those sorts of rates when mostly flying on instruments, back in the era when the requirements of the simulations were always a few steps ahead of affordable hardware. Landings at busy airports were interesting. Not much room for error when the game is lagging the inputs by half a second.
But I can't imagine playing a visually-oriented game like ED at anything less than an absolute minimum of 30fps, and even that would probably give me eye strain after a while.
I'm guessing OP is talking about a laptop here? IIRC even my old Q6600 with a 512MB GPU ran some of the more optimised pre-release ED builds at more than 17fps. Probably not much more, mind.