Anybody tried OSX 10.8 with the Original Mac Pro? According to everymac.com, they are only compatible with 10.7.5. Not sure why.
If memory serves, the official reason why the original Mac Pros aren't supported is because EFI on them is only 32-bit.
That said, it's apparently possible to hack the Mountain Lion installer to work on those machines:
Thanks, that explained why. Back to the original question, any known bad side effect of hacking it? Since EFI is between OS and firmware, how bad is it to have 32 bit EFI with 64 bits OS? Since it worked wit 10.6 and 10.7
I don't have one of those machines, so I can't offer any observations as to how well it would work. However, reading through the link I posted, it sounds like the hack works by using a prior version of some files that still had 32-bit EFI support (which Apple took away for the final release of the OS). It sounds like, to install 10.8, you're effectively turning your Mac Pro into a Hackintosh -- so things like software updates could potentially brick the machine.
So, we are making a Hackintosh out of a real Mac. That's some thing new :). I may just stay with 10.6.8 for now until I get enough to buy a newer Mac Pro. I still using some PPC based software. I was just hoping I could migrate all my Palm stuff over to iPod Touch or iPhone. I am on my very last Palm T5 now. I would like to move on before it bit the dust.