In Accidental Tech Podcast episode 18 (love the show), I learned that John Siracusa was thinking about buying a new Mac Pro for gaming.
I believe that gaming on the new Mac Pro will be a mediocre experience.
Driver support: as John mentioned himself, the video cards are 'professional GPUs' used in workstations for computing, CAD etc. These cards and especially their drivers under Windows are not geared towards gaming performance.
The performance and quality of Mac OS X drivers may be improved dramatically over the past years, but if you like to play games exclusively under Windows, you will probably be disappointed when you switch to bootcamp.
Crossfire support: you have these two ridiculously fast GPU's and for years on the PC platform, you can stack them together to achieve insane performance (SLI / Crossfire).
Mac OS X does not seem to support crossfire (or SLI). If you can't benefit from crossfire, you're paying a lot of money for a machine with one idle but very expensive videocard. That sounds like a ridiculous waste of good money.
Assuming that the hardware supports crossfire, if you would run Windows, then you may hit the driver issues associated with pro cards.
Upgrading: upgrading can be cost-efficient as most games are GPU not CPU bound, not an option for the Mac Pro. Even the new Thunderbolt interface does not have sufficient bandwidth to hook up one or more external high-performance videocards, aside from the fact that this will be insanely expensive.
If you really needs the horsepower of a Mac Pro for other purposes than for gaming, sure it's the fastest mac you can get, but otherwise, I believe there's a better deal to be had.
We don't now what the new Mac Pro will cost in a configuration suitable for gaming, but it will be 'a lot'. I believe that for one new Mac Pro, you will also be able to buy:
- a mac Mini with reasonable specs (it's easy to replace memory and storage);
- a high-quality 27" display @ 2560x1440
- a ridiculously fast PC that will outperform the new Mac Pro when it comes to gaming.
I know that some Mac users don't like the idea of having a PC at home, but if you are into PC gaming, there's no other choice in my opinion if you want a good gaming experience.
I had high hopes for my 27" iMac (2011) but gaming performance anno 2013 is just mediocre at best. And I can't use it as an external display with a PC, only with a Mac.
So I sold my 27" iMac and used the money to buy a separate 27" display and Mac Mini. I also ordered a 'ridiculously fast PC' which I hope will allow me to play all modern games on max quality settings for now and the upcoming year. And if required, I can swap out the dual GPUs and replace them with something better over time, if I need to.