> Trying to open a 10mb file in atom causes it to chew up 1.2gb of ram
Truly?! That's a factor of 100x, that's ridiculous.
TBH, I'd kind of expect an editor to use a factor maybe 2x of the loaded file (for quick access indices, searching, etc). More if you count undo-buffers, of course.
I could well be reading the stats wrong, but yes; really - this is tested on Windows 7 64bit (latest updates). Opening Atom without any plugins, themes or files loaded seems to require approx 150mb just to be alive.