Interesting. This may explain a strange incident that I once encountered. One day I came home to my CSE-847 machine with SATA drives hooked to SAS expanders on an mpt device. The whole system was unresponsive and the drives were all as hot as a fresh pot of coffee. I immediately shut down the system and let the drives cool out on the concrete floor. Everything seemed to work later, but it was quite a scare. It was 12 2TB drives setup as 6 zraid2 mirrors.