Originally Posted by Desolutional
Safe voltage is a personal preference. I'd suggest less than 1.25V if you're using a CLC, and if you have a custom loop, go as high as your temps permit. Staying below 70~75C during stress testing is always a good idea.
Of course you could always use an intelligent throttling limit too; i.e. setting the Core Temperature limit in the BIOS to your max desired temp. The mobo will then throttle/cut off cores depending on how much voltage and heat is being passed through them. You could also fiddle with the turbo power limits which does a similar thing, albeit instead of shutting down cores it will simply throttle the maximum power dissipated through the CPU package.
Voltages are linked to temperatures with CPUs. In the case of "normal" Haswell, the maximum voltages can be higher, as the density of the CPU package is lower (you have less cores inside the package). As a result of thermodynamics, the power output from the quad core CPU is lower than an identical hexcore CPU. With Haswell-E, the cores are packed close, just like Haswell, but you also have more cores. More cores with the same power output = more thermal energy being generated and output. As a result, on average, temperatures with an identical cooling solution are higher than their Haswell counterparts.
*As with all overclocking, you can go as high as your cooling permits - which is why Dry Ice and LN2 can be used to reach mammoth clock speeds and use insane voltages. The basic thing to take from this, is that with equivalent voltages and clock speeds, the Haswell-E processor will generate more "waste" energy than the Haswell processor. The extra "waste" energy needs to be removed via cooling by heatsink. If you use the same heatsink and cooling, the temps will be higher as the heatsink and cooling have to deal with more energy.
Thanks for nice info!
But i have 2 question now after reading all that info..
You say push it if the temp under 70c let we say i have overkill loop and low ambient temp I can push it to 1.4v for 24/7 ? many say the voltage kill the cpu while the temp not ?
also you talk about the temp for haswell vs haswell-E you mean at the same clock or just stock vs stock ? If the later one then its not 100% right
I have the 4790k under Noctua D14 and just upgrade to the 5820k using the same cooler and my temp went down around 10-15c if not more
maybe because 4.4ghz vs 3.6ghz ? also keep in mind 88W with crappy TIM vs 140W with excellent TIM ?Edited by Mr-Dark - 10/18/15 at 12:28pm