IBT is great software to testing stability. Much better than Orthos/Prime95. Before, I used to 3D Mark 2005 Cpu Test, which also stress CPU much - if something is unstable, I've got a reboot. I don't like Orthos, because it takes too much time and I wasn't sure about stability. Now, 5 passes are enough (on my CPU about 180-200 seconds). But my E6420 gets really hot