I bought my MacPro (MacPro 1,1) in September 2006 and nearly 5 years down the line it’s still going strong, or at least it was.
Some recent projects I’ve been involved in have required some serious processing power to render gigapixel images and the original 2xDual Core XEONs weren’t up to it. I found a matching pair of cheap E5345 QUAD core processors on eBay and fitted them (that’s another post that will be on here soon along with photos of the CPU swap out process). I threw some SSD’s in a RAID array in there for good measure too and the combination of those two things made a phenomenal difference to the rendering times. My Snow Leopard 10.6.7 install was nice and stable, not a single crash/hang/kernel panic or reboot.
Then Apple released a Snow Leopard update 10.6.8 to “ready you for Lion” so I dutifully upgraded the 10.6.7 I had installed on my SSD’s and it all went terribly wrong. The system now erratically rebooted itself and a look at the logs showed Kernel Panics all over the place. I have a second OS X 10.6.7 for emegency situations, booted into that and ran that for a few days and it was all fine. I rolled back my 10.6.8 to 10.6.7 using a TimeMachine backup and everything was stable again.