I am about ready to purchase a new octo mac pro and really need a fast machine for rendering purposes. Ideally, I would like the 2.93GHz unit but cost (meaning threats of physical harm from my wife if I should purchase anything "too expensive") is a real concern at the moment. I know that some (tutor comes to mind) have upgraded the processors in their mac pros with success. I am wondering if system I get now will affect my upgrade path in the future. Basically, are the powersupply and heat sinks (and everything else except the processors) the same across all octo models such that I could upgrade to a faster processor at some point in the (hopefully) near future? I saw that the Inquirer placed dual 3.33GHz processors in a unit with a 850 watt power supply and had no trouble (http://www.theinquirer.net/inquirer/review/1529284/dual-xeon-w5590 ), and I think I've read somewhere that apple uses a 1000+ watt power supply for the mac pro. So, I should be good there unless there are different power supplies in different mac pros. Thanks!