[shawnreilly]

I would recommend getting the hd5770 and trying the 10.8 upgrade before going all out on a build for Mavericks. My experiences with 10.8 on Mac Pro 1.1 (flashed to 2.1) have been hit or miss, and I'm honestly not sure about Mavericks. The 10.8 install did work (it booted), but the machine would lock up on me from time to time, and some stuff wouldn't work. It was also obvious that Apple did not want this to work, so maybe they'll put more effort into making sure Mavericks does not work. I concluded that it was not stable enough (for me personally) as a development environment, but maybe it will work out for others. If someone wants to do a Mac Pro build for Mavericks, I'd recommend they start with a 3.1 or 4.1 (something with the 64EFI)

The new Mac Pro 2013 is beautiful man. I'm not the target market, but I can see professional audio/video engineers getting excited about it. Editing 4K video in real time? Pretty badass. I was also impressed with the case engineering, but we'll have to see how it performs. I don't really see the design as form over function. It was designed to use a single fan for the entire machine.

[burrokeet]

Thanks - well I can still use all the performance bumps from the add-ons even if I stay in 10.7, but I'll let you know how it goes with 10.8 to start with.