Is it bad to overclock all the time?

Question

If I enable overclocking and never turn it off, how will that affect my CPU?

IIRC overclocking only kicks in when your CPU actually needs the extra processing power. Overclocking doesn't take affect on idle or when you're doing simple tasks like web browsing.

I'm using the i7-6700k and it comes with 1 of the 4 cores overclocked to 4.2GHz while the other 3 cores are clocked at 4.0GHz. I've set all 4 cores to be overclocked at 4.2GHz and made no changes to the CPU voltage.

I'm running two Noctua Industrial 120mm fans on my radiator at 3,000 RPM. Along with another x2 120mm--as intake--and x1 140mm--as exhaust--Noctua Industrial fans at 3,000 RPM. This keeps my CPU at a cool 19c and my GPU at 26c. The H100i v2 pump is running at 24c. This is all in a Micro ATX Thermaltake V21 for maximum cooling air flow.

This leaves me to believe that overclocking has no potential threat to your system or the lifespan of your CPU until you've hit critical load and critical temperatures.

Solution

This leaves me to believe that overclocking has no potential threat to your system

Uhm, no?

There certainly is a potential threat. Operations are not guaranteed to work at speeds exceeding the manufacturers guaranteed (and well tested!) configuration.

You probably can get away with it, especially if you do are careful; e.g. test the build as good as you can, make sure cooling is up to snuff etc etc. But there are no guarantees and the internal testing at Intel (and AMD and ... etc etc) is likely much more thorough than some burn-in test which you can run at home.

So a potential problem exists.

Having said that: If you just want a gaming system and the worst can happen is an extra crash per month, then go for it. If you build a medical system, then you obviously never risk this.

or the lifespan of your CPU until you've hit critical load and critical temperatures.

Silicon degrades faster at higher temperatures, so it will fail sooner, which does not mean soon. It might very well only work for 10 years rather than a normal 20 years. (Number made up, but long. Usually significantly longer than the lifespan of a desktop).

What you will run into though are higher temperature in your case. You added extra fans, but make sure they do not just cool the CPU. There are voltage modules near it. A modern PC seems to place the disk (M2 socket) near the CPU and those also tend to get very hot.

Lastly, I think you misunderstood intels turbo:

I'm using the i7-6700k and it comes with 1 of the 4 cores overclocked to 4.2GHz

An i7 6700k does not ship with one core overclocked. It ships with four cores capable of running at 4.2GHz, but doing so will generate more heat than the chip can dispose of. To keep heat in limits, the four cores can only sustain a speed of 4.0GHz. If most of the cores are idle and the chip cools down that it can use its power/heat budget to power one core at higher (non-overclocked!) speeds. It will cease to do that when it runs out of heat budget.

This is standard for Intel turbo boost technology version 1 and 2 (and your chip uses version 2).

Comments

[FatalSleep]

Looking at the MSI and previously the Gigabyte BIOS however, one core was indeed clocked at 4.2GHz by default. So whether or not my CPU degrades faster depends mostly on temperature? In which case I shouldn't have a problem here.

[ganesh]

Sillicon has no moveable parts. It has lots of doped silicon which will slowly degrade when the doped (N or P) part migrate. This happens very slowly, but faster at high temperatures. Most of the time it is not something to worry about unless you plan to keep that PC for a very long time (10+ years). I am more worried about heat changes. Cooling and heating is not a good thing where things expand and shrink. Yet it is common and most desktops still last ages. So I guess you can ignore all that unless you want it to be on a spaceship and for for decades.

[ganesh]

As gi Gigabyte (and other brands). Some indeed ship with slightly to fast settings so they are on top of motherboard benchmarks. Often by using a slightly to high block (e.g. at 101MHz rather than 100MHz), but other tricks are also used. Keeping one core at max performance would not surprise me.

[Ramhound]

Worth pointing out that Intel and AND both sell products where one of the selling points is the ability to overclock the product, they product has to be properly cooled and at least Intels warranty doesn't cover overclocking, but it's a design feature of the product all the same

[ganesh]

The black editions and the core -K versions. Yes. I assumed that the OP already know this since he got a i7-6700k rather than a i7-6700

[Ramhound]

@Hennes - I know you know that. Most people don't, and product engineering is a complicated beast, if a chip can be overclocked it was likely left that way purposively