They don't have the same aspect ratio. The Dell is 16:9 while the rMBP is 16:10. They don't have the same resolution either. The rMBP is 2880x1800 while the Del

They don't have the same aspect ratio. The Dell is 16:9 while the rMBP is 16:10. They don't have the same resolution either. The rMBP is 2880x1800 while the Dell is 3200x1800.