I'm guessing this is due to love.timer.step() being called twice somewhere when graphics are disabled, but I'm not sure. You can reproduce this with this code:
local min_dt = 1/60 local next_time = 0
function love.update(dt) if love.timer.getTime() >= next_time then print("FPS: " .. love.timer.getFPS()) next_time = love.timer.getTime() + 1 end
if dt < min_dt then love.timer.sleep(min_dt - dt) end
And in your conf.lua, add the t.modules.graphics = false line (of course.) FPS will be about 120. Now enable graphics, and it's 60. This is LOVE 0.8.0.