[iOS] Scale Image or Create image for multi-resolution

I’m newbie in cocos2d-x. Now I’m developing a new game, actually it is used cocos2d-x. In my other apps, I was used images with multi-suffix (create by texture packer for all of ipad, iphonehd and iphone). so now I don’t know I should use images with multi-suffix or one biggest images then scale it by code? Please give me your advice! thanks!