So why does the 13" rMBP have a higher resolution than the 15".....?

[ducatiti]

I remember reading this somewhere but can't recall why. Can you please elaborate on this thought? Is it the scale or pixel count compared to the size of the screen which makes the 13" higher res?

 

[siurpeeman]

the 15" retina macbook pro has a higher resolution, 2880x1800 vs 2560x1600, though i think it might have more ppi (barely, 227 vs 220).

 

[IllmasterMath]

The 13" has higher pixel density, not resolution. IIRC the difference is negligible.