I launched my app on iphone 6 and 6 plus simulator. iPhone 6 plus uses @x3 images, but this have the same ratio. However, the iPhone 6 have a screen of 1334 x 750 (667 x 375) ... this sucks!
As you probably know, the app screen automatically fit to those new screen. But for the iPhone 6, images are bigger but they cannot be replaced (@3x is only for iphone6+).
How to deal with this new size?
I have to use autolayout only?
How to set the right screen size without automatically rescale this screen?
As Roger answered, you need to add the iPhone 6 and 6+ launch image
But you don't need to use autolayout. AutoLayout is one way of adapting to different screen resolutions, but the old autoresizingmask (springs and struts) is perfectly fine for most layouts. I use a combination of both as they each have pros & cons.