Well, I was curious so I did a direct comparison using the same project running on the same computer. The only thing different is one time I ran the project in Windows 7 and the other time in OS X Yosemite 10.10.5. I did a screen recording of the results on both platforms and slapped together a video. The results are surprising to me as to how close the performance is.
I’m now wondering how close the performance gap is between Logic and Cubase on OS X. Here is the link to the video below: