well if i understood the phone of the video is the same model that you have??
so the flash menu is more slow that the video and that you want??
well if is not the same model the reazon is simple the w850 has a better procesor than others old one (like w600) and obviously the speed of the fps is lower

but if its the same model really i dont have an explanation
i only can say: or itīs the flash menu ( is not for you resolution)