[Kanashimu]

So, thought experiment here. I have a CPU. It clocks at 5 ghz @ 1.5Vcore. Obviously, that is a somewhat high voltage, so we don't want to be stuck at 1.5 all day. Since it doesn't usually need to run at full load, it dynamically underclocks itself to as low as 1 ghz, running at 1.0V at absolute idle. When the load varies, the clockspeed and voltage can vary in between these values. However, even while idling, the Vcore rarely stays at 1.0; it does spike and fluctuate a lot as well.

I'm thinking - what would be better for the health of the CPU? To have a 1.0V baseline and fluctuate between that and 1.5V? Or to have a 1.2V baseline? Or even 1.3?

Thoughts? Science? Opinions?

 

[TwoCables]

The fluctuation is normal, and there's actually a lot more fluctuation than any software can show us. If we were able to see exactly how much fluctuation there really is, then we would probably panic and then faint.

I think I don't know much, so my feelings are that it seems best to allow the CPU to downclock to 1.6 GHz and to downvolt to the 1.0V range. I also have C3 and C6 enabled, but I can get away with this because I'm also using 25% LLC (Medium for my ASUS board, so probably level 4 or so for you). This means that when my CPU is truly idling and has entered the C6 state, it's not consuming any power at all - it's actually sitting at 0V. However, software like CPU-Z can't show this because it has to keep at least one core awake which means it's going to be showing that one core sitting in the 1.0V range.

So yeah, I guess I prefer an Offset voltage, 25% LLC, C3 and C6 enabled (C1E and SpeedStep enabled too), and there's something else I forgot to mention: I have my power plan in Windows customized so that my minimum processor state is 0%, and my maximum is, of course, at 100%. I don't know if this makes any difference, but it's not hurting anything.

By enabling C3 and C6, I saw a ~15W reduction in my idle power consumption.