I did a test recently, calibrating and profiling the same Dell U2711 monitor connected to my PC (win
, and them on my Mac (10.8.4). I used the latest ArgyllCMS and DispcalGUI on both platforms, with the Same i1Display Pro sensor. I was quite surprised to see the difference between the two calibrations (see attached color accuracy measurements).
I used the same methodology and calculation spreadsheet for both, as detailed here (http://stephenstuff.wordpress.com/2011/06/26/complete-display-calibration-with-argyll-cms/
) - Great tool BTW!
The Win8 calibration and profile is shockingly accurate, while the Mac OS one is quite horrible. I have to wonder if the problem lies within the ArgyllCMS packages on either platform, or in the color management system within the OS. Visually, I could tell that some of the patches were off on the Mac also.
On another note; I was very pleasantly impressed with the performance under Win8. I didn't think the U2711 would have been that accurate. There is some variance in uniformity of about -15% in the lower left corner, so it's not perfect, but for the price, it's quite impressive.