4790k Overclock on water

[Zailyn]

Hi, I got a build set up around a week ago. It has a 4790K CPU and is cooled by a 3x120mm radiator. I watched linus's video regarding the 4790k and got some ideas from it, but I am still uncertain about some things. I am currently running the CPU at 4.6Ghz at 1.20V and temps do not reach the 70C mark and the system is stable. No BSOD's or any programs acting weird. I am curios if the system can go above this mark but am not sure what my max voltage should be. Linus says 1.300V, but can it be higher since it is cooled by water ?

 

I would love to get the MAX OC I can from it. I tried to auto 4790K @ 4.8Ghz that was with the motherboard and it was TERRIBLE. Sure the system ran stable but the voltage was 1.80V, good thing I had noticed.

 

Any advice and help anyone can give me ? Specifically, is 4.6Ghz at 1.2V good ?; What would you say to be the max voltage for a 4790k cooled by water ?

 

Thank you

[Bananasplit_00]

4.6Ghz at 1.2V is really good, i can get 4.7Ghz on my 4690K at 1.335V(only in the winter tho  ) so i would say thats a great overclock

[Zailyn]

1 hour ago, Bananasplit_00 said:

4.6Ghz at 1.2V is really good, i can get 4.7Ghz on my 4690K at 1.335V(only in the winter tho  ) so i would say thats a great overclock

Hmm interesting to hear. I need to find out what the max voltage should be on water. Any idea ?

[Bananasplit_00]

1 minute ago, Zailyn said:

Hmm interesting to hear. I need to find out what the max voltage should be on water. Any idea ?

i would never go past 1.4V, after that it can hurt your CPU, and for a computer i care about never over 1.35V

[Zailyn]

1 hour ago, Bananasplit_00 said:

i would never go past 1.4V, after that it can hurt your CPU, and for a computer i care about never over 1.35V

So, you would say 1.35V as a max ?

[Bananasplit_00]

2 minutes ago, Zailyn said:

So, you would say 1.35V as a max ?

maby a tad higher on water if it makes it stabile but yah, try to keep it under 1.35V

[Zailyn]

I'll try it out. Thanks

 

[aisle9]

9 minutes ago, Zailyn said:

Hmm interesting to hear. I need to find out what the max voltage should be on water. Any idea ?

Type of cooling doesn't really change the max safe voltage. It just changes the maximum practical voltage by lowering heat.  with my H5 Ultimate, voltages above ~1.275 generate unacceptable levels of heat during stress testing.

 

My hard cap is 1.3v for my 4790K; I don't intend to play fast and loose with voltage on a $300 CPU. Given that, I could almost certainly milk another 100MHz out of it, but that's as far as I'd be willing to go, and the 4% bump in performance isn't worth $125 to me. Your overclock right now gives you plenty of room to push forward, and is slightly Godmode. How'd you stress and verify it?

[Zailyn]

1 hour ago, aisle9 said:

Type of cooling doesn't really change the max safe voltage. It just changes the maximum practical voltage by lowering heat.  with my H5 Ultimate, voltages above ~1.275 generate unacceptable levels of heat during stress testing.

 

My hard cap is 1.3v for my 4790K; I don't intend to play fast and loose with voltage on a $300 CPU. Given that, I could almost certainly milk another 100MHz out of it, but that's as far as I'd be willing to go, and the 4% bump in performance isn't worth $125 to me. Your overclock right now gives you plenty of room to push forward, and is slightly Godmode. How'd you stress and verify it?

I left Prime95 running for several hours without any problems. It has been at this setting for the past 5 days and till now, no problems have occured. Even though the OC looks good, the CPU doesn't like anything above 4.7Ghz. It can reach 4.7Ghz at 1.25V and ran a few tests without problems ( but I did not really test it that much )

 

4.8Ghz seems too far. The PC won't even boot unless it is at 1.33V. I don't think the performance is worth the voltage, both for the 4.7Ghz and 4.8Ghz.

 

Any recommendations to fully test out my OC ?

Thanks

[aisle9]

4 minutes ago, Zailyn said:

I left Prime95 running for several hours without any problems. It has been at this setting for the past 5 days and till now, no problems have occured. Even though the OC looks good, the CPU doesn't like anything above 4.7Ghz. It can reach 4.7Ghz at 1.25V and ran a few tests without problems ( but I did not really test it that much )

 

4.8Ghz seems too far. The PC won't even boot unless it is at 1.33V. I don't think the performance is worth the voltage, both for the 4.7Ghz and 4.8Ghz.

 

Any recommendations to fully test out my OC ?

Thanks

I have my own verification process written down on my profile page. I generally avoid P95 on Haswell, as it can trigger a bug that pumps too much voltage onto your chip, artificially raising temps and, more importantly, potentially damaging it. With your voltage as low as it is, I doubt that will be an issue for you, but it's something to consider as you move forward.

[Zailyn]

1 hour ago, aisle9 said:

Type of cooling doesn't really change the max safe voltage. It just changes the maximum practical voltage by lowering heat.  with my H5 Ultimate, voltages above ~1.275 generate unacceptable levels of heat during stress testing.

 

My hard cap is 1.3v for my 4790K; I don't intend to play fast and loose with voltage on a $300 CPU. Given that, I could almost certainly milk another 100MHz out of it, but that's as far as I'd be willing to go, and the 4% bump in performance isn't worth $125 to me. Your overclock right now gives you plenty of room to push forward, and is slightly Godmode. How'd you stress and verify it?

I'll try out your method then  . Thanks

[ThomasD]

You could get the intel insurance (Performance Tuning Protection Plan) and they'll replace your CPU once if you fry it.

 

But, given what you have now, which looks like a good one, personally I wouldn't risk it - the odds are your replacement would not be as sweet.

 

So, for a 24/7 OC you probably do not want to push much passed 1.3 volts.  Yes, better cooling makes things better, but based on my experience with two 4790Ks under water (both Corsair 280s) temperature does not become an issue until you are well past 1.3 volts.  That's just the way this CPU seems to roll.

 

If it were me I'd try to find the lowest voltage that will be stable at 4.8 and call it good.  Otherwise, if you are curious, see if it can reach 5.0 at less than 1.325 volts.

[Zailyn]

1 hour ago, ThomasD said:

You could get the intel insurance (Performance Tuning Protection Plan) and they'll replace your CPU once if you fry it.

 

But, given what you have now, which looks like a good one, personally I wouldn't risk it - the odds are your replacement would not be as sweet.

 

So, for a 24/7 OC you probably do not want to push much passed 1.3 volts.  Yes, better cooling makes things better, but based on my experience with two 4790Ks under water (both Corsair 280s) temperature does not become an issue until you are well past 1.3 volts.  That's just the way this CPU seems to roll.

 

If it were me I'd try to find the lowest voltage that will be stable at 4.8 and call it good.  Otherwise, if you are curious, see if it can reach 5.0 at less than 1.325 volts.

It won't even be close at 5Ghz 1.325V. It won't boot at 4.8Ghz unless it is more than 1.3V and I dont even know if that is stable