The MacPro 2,1 was a BTO MacPro 1,1 with quad-core 3.0GHz CPUs available in 2007. Many folks here, including me, upgraded their MacPro1,1 (2006) models on their own with the same quad-core 3.0GHz CPUs. I had been told that the MacPro 2,1 firmware includes the Intel Xeon microcode for the X5365 CPUs, and that microcode is not included in the MacPro 1,1 firmware, along with different fan settings. I do not know if this is true, or even if it is, if it matters as clearly the quad-core CPUs work fine in the MacPro 1,1. Has anyone attempted to load the MacPro 2,1 EFI firmware and SMC firmware on these upgraded MacPro 1,1 boxes?