So far I've succesfully overclocked my Z87 Extreme 6 with i7-4770K to 4.6GHz on 1.275V ... (tried 4.7GHz as well, but I did not yet want to push the voltage over 1.3V to get it stable - Handbrake crashed after a few minutes). At 4.6GHz and with AIDA64 stability testing, the temperatures reach the mid to high 80's on air (as expected for Haswell) which works for me.

However, this overclock is using the "Override voltage" setting (which also uses this same voltage when idle, keeping the idle temps in the high 30's), and what I really want to use is Haswell's adaptive voltage to give me 1.275V at high load. I don't understand how to configure it though, the manual (quoted below) and the help messages in UEFI (identical to the manual) do not make sense to me. They both say "add voltage", and playing around a little with the values only caused quick crashes and/or temperatures way outside my desired range.

CPU Override Voltage
Configure the voltage added to the CPU when the system is under heavy load.

CPU Voltage Offset
Configure the dynamic CPU voltage added to the CPU.
Can someone help me to explain what exactly these settings do, and help me to get the right settings so I reach my desired 1.275V under load?


Setup: I don't think my setup it's relevant, but since people might be interested anyway ... NZXT Phantom 630 case (fully loaded with fans), Noctua NH-D14 cooler, Corsair HX620 PSU, Kingston HyperX Beast 2400 CL11 2x8GB RAM, OS drive is a yet to be replaced old OCZ Vertex 64GB, my storage is 4x640GB using raid 1+0, and the yet to be replaced graphics card is an Asus HD5870 1GB.