I have a Mac Pro 1,1 (2006 model). Does anyone know if it is possible to run his machine using a single CPU chip instead of a two? The new LGA 771 quad core chips (e.g., 5420) have more performance in a single chip that the dual 5150s in this machine. It's pretty expensive to buy two 5450s to maintain the dual-CPU chip configuration, but a single chip upgrade would make sense. Most non-Apple dual processor motherboards will run with only a single CPU. I'm curious is anyone has tried this with a Mac Pro. Thanks.