Load Line Calibration for CPU Vcore

[John_Au]

Hello,
I have read on a couple of guides that using LLC of High (50%) or more is dangerous for 24/7 overclocks.

But on other forums i've seen people saying there is no issue running ultra 24/7 and have been for 2 years without signs of performance degradation.

I've got a Rampage IV Black Edition with 4930K, Just wondering what exactly it is about LLC that makes things dangerous, and what would be the dangers of using High or more LLC.

From my understand LLC counters Vdroop (the voltage drop from Load to Idle) to prevent voltage dropping too low during load changes and causing BSOD. (please correct me if my understanding is wrong - as i'm not sure)
Beyond that I don't really understand how this process works.

If LLC is set to high, but voltages still seem to be below 1.4V on ROG conenct/RC Tweak It readings, could that be interpreted as safe 24/7?

Thanks,
John

[jab383]

Intel wants the Vcore to droop at higher load in order to stay within the Thermal Design Profile (TDP) of the chip and to reduce the chances of thermal throttling at the highest loads. They call this a load line droop. With good cooling and a ROG motherboard, we are less concerned with the thermal and power limits. Accordingly, we can use less droop - a load line compensation (LLC), take higher power consumption at high loads and the CPU temperature still stays in bounds.

When cooling is very good - custom water loop or very efficient all-in-one water - LLC can be set so Vcore actually rises under load. That way the core gets more voltage just when it is susceptible to crash, freeze or bluescreen. With my R4E, Vcore rises slightly at load - about .02v - with the Ultra High setting I use for most benching.

The Extreme setting makes Vcore rise more with load. That's where the danger is. Voltage, power at high load and therefore temperature can increase beyond what is planned for. With extreme cooling - phase change, dry ice, LN2 - temperatures stay in bounds and extreme overclockers can get their scores.

You don't say what cooling is used and I have mentioned where and why that is important. With water cooling, I consider Ultra High safe for 24/7 use. If 24/7 use sees peak load only rarely, there should be no harm at all. If there is a lot of benchmarking with an overclocked and stressed CPU, see to the cooling first.

Jeff

[John_Au]

Thanks for your explanation, jab. Yeah i have a custom loop with 3 rads (120, 240 and 360) which does an alright job at keeping the temperatures fairly steady (it seems much more beneficial on my gfx cards than the cpu, i have two 780 ti SLI which never see above 41C at 99% load)..
I've been trying to overclock my cpu a bit further (as it had a bit of room to move temperature wise) but have been limited by LLC setting (wasn't confident on running LLC over medium because of something i had read in the past).
Now that i understand a bit more about the setting I will probably take it up to High, as I was able to get another few hundred mhz higher using that setting, but was not keen on running it 24/7)
Thanks again.