Hello,
Question for anyone who is running the MacPro 5,1 firmware on the 3,1 Xserve using the x5690 CPU's (assuming that is the fastest you can get), how is the noise on the server? Does the fan array stay quiet except when there is load on the system, or does it ramp up at 100% because it is an unsupported CPU or unsupported firmware? I'm running the x5570 2.93 GHz CPU's in my 3,1 right now with the latest stock firmware. The Fans respond properly and they only are loud during initial boot and under high CPU / high heat conditions. I had put in the 3.33 CPU's a while back, with those CPU's which were never supported with the 3,1 firmware, the fans run at 100% and the thing is just way too loud. I'd consider the MacPro 5,1 firmware hack to put in x5690's, but only if the fan array works properly. There is no way to silence the box otherwise.