In this thread, Nick explains that:
I followed the recommandation and my rig can handle it. Overall, with my P3D settings, I get 50-70fps. I tried to lower the texture resolution to 2048 x 2048 and could barely see the difference in the cockpit. All is still sharp. I have a 2K monitor.The Bonanza features high-resolution (4096 x 4096 pixels) texture sheets for the virtual cockpit and external texturing.
What is your experience?
It seems to me that most of the time, addons textures (aircrafts and sceneries) are 2048 x 2048, only a few do have 4096 x 4096. Is that correct?