LLC is a must for high stable overclocks its why I ditched my UD3 R1.0
My sabertooth R2.0 gets 5ghz on the same voltage as I could only get 4.75ghz stable on the UD3. Also runs cooler because the voltage isnt all over the place.
If you mange to get 5ghz stable on the UD3 I bet with a better board youd get 5.1ghz stable on the same voltage.
voltage is kinda all over the place, but that is because i use Cool and Quiet. Well scratch that, i use Mr phenoms tweaker for custom cool and quiet.
I have been to 5.2ghz when it was 30 degrees outside, and i left the window open. I just set the voltage in bios to 1.6volts, then under load it would drop to around 1.54 or so. With cool and quiet my voltage was never 1.6 volts anyways, so it was safe. All this on the Ud3 rev 1.0.
I know a few other Ud3 guys who have accomplished quite high clocks, I personally don't think its the board, but the user and the setup. I do understand more people seem to get better overclocks on the Crosshair V. I might grab the Crosshair V Formula Z if i can find a good deal on one. Then sell my UD3.
So far though i've had nothing but success with the Ud3. I'm rocking 4.9ghz daily 24/7 on my 8120 with 1.45 volts. I can run 5ghz at 1.5 volts but my Poor Antec 920 doesn't like the extra heat, and i don't like the extra racket that comes from its loud annoying fans. Thus I decided to go to custom water loop. Will soon have a XSPC Rx 240+140mm dual radiator For a total of 520 of radiator madness for just the CPU. I will say i will be cooling the chipset and my 7950 as well when i get the funds for the blocks. Though i cannot decide if i want to upgrade to the Crosshair formula Z before i get the chipset blocks.