So searching through the forums here, I decided to get a Radeon 4870 for my Mac Pro 2008. Put it in my machine, all happy to hack this baby and play Starcraft 2 smoothly. Turned the machine on, it's not booting, and I smell electronic burning. Ut oh. Turn it off, take out the card, try to boot. Nope. Machine does nothing for a little bit, then slowly the fans go to maximum power. Tried resetting the PMU, unplug computer, hold down power for 5 seconds, and still the same issue. So what are my options here? I haven't called Apple because it's out of warranty. Looking around, apparently it's a $1000 logic board replacement. That's nuts. I'd rather just sell my MacBook here and get a MacBook Pro to replace both machines.