Posted by Demoscene Passivist on May 10, 2011; 3:24pm
URL: https://forum.jogamp.org/Rendering-and-displaying-different-resolutions-tp2903765p2923448.html

>is it going to be much / any faster than just rendering the scene outright?

... depends on the complexity of ur scene, but rendering to a FBO and doing a second render pass to display the fullscreen quad with the FBO as texture is basically free. U can do hundreds or even thousand of these passes per frame  on a modern GPU (as u would e.g. to achieve blur or other filter operations).