OS X is terrible at graphics and Open GL:
Let me give you some hard empirical data:
First, I actually teach computer science at a university. It doesn't make me an expert or a god or anything like that, but I really know what I'm doing when it comes to programming, compiling, optimizing, and look at an OS's subsystem.
I have a MBP (see my sig). If I try to compile the same graphic app under Windows (via BC) and also under OS X, OS X will consistently be 15 fps (or more) SLOWER than Windows.
I'm not talking DirectX vs OpenGL, I'm talking straight OpenGL apps.
You want to know how bad it is? For two weeks I thought I was doing something wrong with my compiles. I checked everything (gcc, my makefile, my headers, etc...) and even went back to Apple Dev to see why there was such a huge gap on the same hardware between OS X and Windows.
I finally went to some forums to investigate and have found many people in the same situation. It eventually led me to a thread with some of the programmers of Dolphin (GC emulator).
Dolphin is not perfect but its mature enough that I think you could use it for some useable benchmarks on graphics when you compile a version of Windows and one for OS X.
I could not get the same performance out of Dolphin under OpenGL that I could get under Windows maxed out. In the beginning I felt that the performance gap was too wide and I could find some optimizations and compile changes to bring it much closer. I could not.
Far from being perfect, I emailed others who were compiling for both Windows and OS X and asked about their experiences. They too were getting the same results.
I was shocked to say the least.
If we broaden our experiments to other games for both PC and Mac its also easy to see which is faster (even if you eliminate Direct X) but you also introduce variables that make any concrete benchmarks worthless. Cider for example is just WINE which obviously throws any results.
So lets ask a simple question: Why? Why is it so much slower?
I can only make educated guesses but the most common 'guess' I've heard is that OS X video drivers are at fault for a number of reasons:
-Apple doesn't care about optimizing and its better to have a basic driver that covers many families of the video chip. You could (maybe) argue this buys you stability over performance but that is iffy.
-ATi/nVidia are pushing for Windows so Unix/Linux suffer and Apple does not (cannot?) do anything to improve them.
-NextStep was incredibly slow with graphics (being PostScript based) and perhaps that handling of the graphics by the OS is still in place. Again, you are thinking stable OS, sharp graphics (not game graphics), portable code, etc..maybe.
I would love to talk with the OS X group about this because 10.6.x isn't exactly new and they have had the time to mature the graphics driver and subsystem so I don't know what the deal here is.
I can only post empirical based evidence and I can say in my testing, OS X is just slow when it comes to games and fast graphic manipulation.
I really do love OS X so I wish this would change under 10.7 but I doubt it will.
Cheers!
P