thanks a lot, all of you for your help. I visited the sites you refered and got some good info about the subject. Some hours ago i added a 2nd cooler and now the temp is much lower. I'm thinking to build my own water cooling system,it doesnt look that hard and probably would have fun. The noise of the air coolers it's not the most interesting sound you can have
AMD really rocks, amazing power in a great price. For sure they'll take a huge % on a server market through time with their new upcoming models. Kimmykim, you did the right thing. Intel Xeon is so fucking expensive that i dont think it worths the $$ If you have solve the heat and the stability(if there's any) issues then you have the perfect server.
many thanks again for your replies