I got 4.8ghz @ 1.392V with max temps in the 60's (on water). I can boot and use windows at 5ghz 1.45V but soon as I attempt a stress test its over with lol. I could probably get it stable with a bit more voltage but I would be afraid to stress test the CPU with that much voltage. If you are stable at 1.33 for 4.6 I think you can go higher. Intel and Asus says 1.45 Max voltage so I had planned to go with whatever I could hit at a max of 1.4V to be a little safer.