My Mac Pro 2009 4,1 was getting long in the tooth and I was looking into upgrading it or replacing it. I opted to try and upgrade it with dual procesors to be a 2010/2012 5,1 Mac Pro and dump a lot of RAM in there. It wasn't too bad of a job, just a bit tricky to get the torque correct when tightening down the heat sink. Wasn't able to find the correct torque specs so just went slow, tested and retorqued a few times before the errors stopped coming up. Its running great now and is a great machine. The extra RAM really helps; PhotoShop had no problems working with a 5 gig file with 300 layers.