what voltage should I use?

Solution
Start low and work your way up with stability tests.
It's really hard to give a range even on Haswell chips since the silicon lottery is very very apparent in that range of chips, some can't even make it past the low 4ghz range.
Start at the stock voltage you see, push the multiplier up, stress test, up the voltage if the stress test fails/becomes unstable and so-on.
Start low and work your way up with stability tests.
It's really hard to give a range even on Haswell chips since the silicon lottery is very very apparent in that range of chips, some can't even make it past the low 4ghz range.
Start at the stock voltage you see, push the multiplier up, stress test, up the voltage if the stress test fails/becomes unstable and so-on.
 
Solution