Retina displays are the full actual resolution. For example, the Macbook Retina I'm typing on has a physical resolution of 2880x1800 and the GPU is physically rendering all those pixels. What you've just said actually makes no sense whatsoever. Multiplication of pixels in a 1:4 ratio of a smaller resolution? Making smaller resolutions just "blown up". WTF does that actually mean?
You can run the retina display at native mode but everything will be half the size (physically) on the screen. The standard default mode for the retina display keeps all your elements the same "physical" size on your screen but renders them with four times the pixels (1:2 ratio) to increase the detail and crispness of text and images.