What are the consequences of running the 13" Retina MBP in higher native resolutions This question is basically about how do different resolution settings affect the performance of your MacBook.

By default retinas are set at the "retina" display mode. You can also set them to the "more space mode", and with 3rd party tools you can go native (much higher)!

But what I want to know is, how does "upping" the res affect the performance of the mac, in particular how does going beyond the retina option affect:


The CPU
The GPU
IO?
RAM (I imagine there is no effect here?)
Battery life (I imagine this depends on how much the CPU/GPU is affected?)


And if any of these are affected, is the relationship 1:1, or exponential, or what?
From personal experience, the resolution has little impact of the 5 aspects listed. However, for me, there's a 6th and this seems to be affected quite a lot. Namely myself. I find that tiny fonts will make my eyes squint and I need to use more brainpower to read StackExchange questions, leaving a little less available to understand some of the remarkable comments left below the question (especially since the font is even smaller for those). My own battery life is severely degraded and I think I'll need to hit the sack in an hour or so. Damn it, that's it, I'll switch to 'Best for Retina', can't even see where the submit button is!