As owner of many various mac pro include: 4,1 Dual + 4,1 Single + 3,1. Although some of them are still fast (e.g. 12-core 2.93+GTX680+4xRaid0 SSD), i realise that my mac pro aging (my 12-core just pass 5 years of heavily use). However, as i still cannot effort on a new model (need to pay $8000 to get a faster system). I trying to use my aging mac pro for a years or two. In a manner that, i keep in mind that 6-years old mac can be failure anytime. So, i have to ask MR that how your mac pro still works, are you got any problems? PS. i also own 2 of powermac g5 (1x1.8 2003 model, 2x2.5 2004) and powermac g4 (2x867 MDD) three of them still working beautifully.