Opinions please. Is it worth the voltage increase for a 100MHz clock speed bump?

[1kca]

I have an i7 4770k which runs happily enough at 4.4GHz at 1.31v. Temps are between 29C and 31C @ idle and max out at about 61C under load, although that's a conservative estimate as I haven't tested this extensively since upgrading my cooling.

My chip is 100% stable at 4.3GHz at 1.25v and possibly lower, but requires 1.31v to be stable at 4.4GHz.

My question is:
Is the performance difference worth the voltage bump to get from 4.3GHz to 4.4GHz? And would it be worth trying for 4.5GHz and higher?

 

[anbello262]

No, I don't think it's worth it. It will be much safer and cooler at 1.25, and only 100MHz is negligible. It's about 2% theoretically, so basically null.

 

[1kca]

2%? Is it really that low?

Given my current temps, would you personally push for 4.5+ or scale it back to 4.3? If 100MHz is only 2% roughly, then 4.5+ doesn't seem worth it in my case

 

[anbello262]

I personally don't think it's worth it. 4.3 is more than enough for basically anything, and once you hit a point that requires a big amount of voltage, it will probably need more and more.
I wouldn't keep pushing it higher, as the difference will be quite marginal. It's a good overclock for that chip.
The calculation I made is quite simple: (100MHz/4300MHz)*100%=2.3%
And it is recommended toleave the voltage below 1.3 if possible, as it is the safest voltage range.

 

[1kca]

That makes sense. Thank for that.

I understand that they're both important but what is more of a threat to a CPU, excessive voltage or excessive heat?
And is there a voltage range where Haswell chips, or any CPUs really, begin to degrade?

 

[anbello262]

Degradation happens rapidly when a combination of both factors are present (high voltage and high temps).
Both are equally negative, but voltage is a lot more sensitive. A short spike of high voltage can make a lot more damage than a whole day of high temperature.
For Haswell chips, degradation is known to happen at or above 1.4V, but it is recommended to stay below 1.3V, to ensure safety.

Some serious overclockers will overclock with 1.4V or more, and many succeed with no problems, but it's a big risk and generally those people don't suffer too much if a chip dies. They just replace it.
For the rest of us, who can't really afford replacing the chips, and those who really care and love their systems (especially if you want it to last a long time) it's better to just leave it below 1.3.

 

[1kca]

Thanks for that explanation, I understand completely. Looks like I'll be scaling it down to 4.3

 

[anbello262]

Here's a nice explanation from another forum:
http://www.overclock.net/t/1411077/haswell-overclocking-guide-with-statistics/15970#post_23091704

You might notice that at www.overclock.net people tend to use higher voltages though. As the names says, they are more used to overclock usually. Here at Tom's people will always be on the safer side, to protect your system as much as possible.