Tnx for a long and detailed reply but it dones not awnser my question.
As I said I had tried to find a list with what CPU the motherbord supports and I have used both this forum and google.
My question is not about watt, heatsinks and Xenon 5300 series. It is simply if Xenon from the 5400 series can work with the motherboard.
I am not about to upgrade it for my self and I will not buy a new CPU for it. I am not using my xw8400 at the moment and a friend that have a CPU from the Xenon 5400 series have given me an offer for the worksation but he wants to know if he can use his CPU on the motherboard.