50d Live View Aspect Ratio During Record

[visiono]

display --- Advanced settings--- Screen Layout 


I heard you should turn off Global Draw, but if i do that soon as i hit record in mlv raw my lv screen jumps into almost a 4/3 aspect ratio. i consider that useless since i shoot 1.85.

So, must i have global draw on then? no other option?

[visiono]

can anyone answer this please? I hear turning off global Draw will give me faster write speeds, but obviously i must see the framing acurately  in 2.35  aspect ratio.