Hi, I've just recently upgraded my 4.1 8 core 2009 Mac Pro to a 5.1 12 core 2.93 using the 5.1 firmware update and the CPU swap. It's great but was an utter pain! However at work I've another 2009 Quad core (2.66) Mac Pro and was considering trying to do a CPU swap on it too. Whilst looking around I have found a 2010 model (5.1) dual CPU daughterboard for sale (complete with heatsinks & CPU's). My question is this... Can I use this 2010 daughterboard in a 2009 Mac Pro which has had the 5.1 firmware update? Or is this likely to kill the motherboard? It'd be great being able to just slide the existing tray out and slide in this tray in and be done! or is that too good to be true? Is there likely to have been any significant changes between the 2009 and 2010 daughterboards? I know I can upgrade it like I've done my last Mac, but if this tray swap was compatible, it'd be MUCH easier. If anyone knows the answer I'd be very grateful if they'd share it. Many thanks.