# Underclocking 4790K



## tabascosauz (Nov 8, 2015)

Calling all underclockers! It's time to step out from the shadows of your overclocking brethren 

I've been fooling around today with my 4790K and relatively new H97N-WIFI, especially enjoying the voltage control offered by this board that was sorely missed on my late H81I. I got around to lowering the clocks and volts a bit on my 4790K. This is in the light of recent developments that may push me to abandoning my SG08 (and re-assigning my D9L to another rig) for an SG05 and a L9i or L9x65.

So, pre-emptively for a decision I might be forced to make, I naturally wanted to make my 4790K run a bit cooler. After some messing around and a few failed boots due to some overly ambitious undervolting, I settled on 3.3GHz, 4c/8t, with vcore at 1.05v. The result was most cores under 60 degrees and one peaking at 63.






I'm no expert at undervolting and underclocking, thus I must ask the undervolters amongst you; so, *do you think that I could go further with this* (higher clock at 1.05v, lower volts at 3.3GHz)? I think I could make do with 3.3GHz on a daily basis; I don't play games that much anymore and the few games I play either don't care much about IPC (PD2 doesn't care much about CPUs at all) or utilise multiple cores pretty well (GTA V). I guess a better question is should I go further or is this enough to keep under 80 degrees in an SG05 with L9i?

I believe stock voltage, at 4.0GHz was around 1.19v vcore. I think that number may have gone over 1.2v at 4.4GHz turbo.

PS these numbers are in a closed SG08 with a NF-A14 over top, and a D9L with just the stock NF-A9 fan.


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## OneMoar (Nov 8, 2015)

60c isn't even warm for haswell
you can safely run it all the way up to 80c at overclocked speeds @ < 1.30v
your chip looks pretty decent mine needs 1.30v for 4.4


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## CrackerJack (Nov 8, 2015)

Currently i'm at 1.26v and 4.5GHz, highest temps I've reach is around ~75c. If I lower the voltage anymore (.01 increments) I can't get past Windows loading.


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## manofthem (Nov 8, 2015)

Fwiw my 4790 non-k runs at 3.8 @1.08v. Any lower and it crashes. If you're only going for 3.3, no harm in dropping a little more to see if it can handle it .


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## johnspack (Nov 8, 2015)

Jeez,  those temps.  If I ever saw 75c running anything on it,  I'll pull the cord....  and I thought my first gen hex ran hot!


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## F-Zero (Nov 8, 2015)

I keep my 4790K at 4Ghz (Turbo Off) but i reduced the voltage with adaptive mode in Bios. So when the Cpu idles it stays at 0.760V~0.765V, in full load it goes no more than 1.047V. I tested for stability issues and had no problems.
After 15 minutes of stress testing in Intel XTU it doesn't go over 47°C. I have to test if i can go any lower but i don't have the time right now.




As for your question:  You should be able to go 4Ghz with your current 1.052V and reduce the voltage even more for 3.3Ghz.

But remember every Cpu is different. The numbers i wrote for my voltage maybe won't work with your Cpu.
Keep us updated.


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## tabascosauz (Nov 8, 2015)

Apparently, I was being very conservative with my figures. This is the second pass around on 4.0GHz @ 0.98V. This is actually getting me a little worried as I'm wondering if I'm doing it correctly, if my 4790K is stable for 15 minutes at 4 cores 4.0GHz at just 0.98V.


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## F-Zero (Nov 8, 2015)

How do you lower your voltage ? Are you using Intel XTU program or from BIOS ?


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## Bo$$ (Nov 8, 2015)

Yes i think you can go further!

However I'd probably change stuff in the BIOS rather than XTU. What program are you using for stress testing?


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## tabascosauz (Nov 8, 2015)

I'm not using XTU to change settings because it doesn't stick; I change all my stuff in the BIOS. Stress test is done via XTU and OCCT; XTU is decent but OCCT stresses 100% of the time and that's a bit too much heat in a closed case like the SG08. There's nothing that can get by XTU but not OCCT; either it passes both or fails both.



Scratch that, 0.987 is not stable at 4. I don't think I really need to hit 4, so I'm going to stay under 1v at 3.5GHz. Sitting at 0.971v and it appears to be stable.


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## ISI300 (Nov 9, 2015)

I got a 4690K which is the same chip as your 4790K except 2megs of cache gimped and HT disabled, and this is the voltage I see after I've dropped it at the same frequency by 100 millivolts:


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## trog100 (Nov 10, 2015)

my 4790 is okay at 4.6 with 1.28 volts.. at 4.5 its okay at 1.27.. to go higher than 4.6 requires a big jump in the vcore for stability maybe 1.35 or higher.. 

stock its at 1.17 boosting to 4.2 gig.. gaming temps are maybe 60 C-ish at stock and 72-ish at 4.6.. it still hits 100C and throttles down when i run a small block FPU only stress load on it..

i would guess with a stock intel cooler  100 C at stock speeds would be quite common when all eight cores are fully loaded.. the chips will stand this else intel would not sell them set at this.. low temps are nice but the chips are designed to hit 100 C.. when they do they throttle down to maintain 100 C..

intel could set them to throttle down at say 90 C.. the fact they pick 100 C means the chip is okay at that temp.. or lets say it wont damage it..

unless you have a laptop there aint much to be gained by running slow.. interesting to see though.. 

trog


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## RCoon (Nov 10, 2015)

johnspack said:


> If I ever saw 75c running anything on it, I'll pull the cord



That's pretty silly. You'd do more damage pulling the plug than running an Intel CPU at 75 degrees. Devil's Canyon and most modern Intel's have a safe operating temperature of over 100 degrees.

It's AMD CPUs that start getting dangerous around 68 degrees. Their temperature reporting is different to Intel's.


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## vega22 (Nov 10, 2015)

my 4770k use to make me shit bricks when it hit 110c...


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## EarthDog (Nov 10, 2015)

Underclocking... I...I...... *points large caliber handgun at head... pulls trigger*


Anyway, jokes aside, can you go lower? Who knows. Test it. Every CPU is different! So even someone with the same model board/bios, and CPU, results will be different. 


*wipes up mess... reads first post again... points same gun at head, finishes job*


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## BarbaricSoul (Nov 10, 2015)

I'm ok with this-






6 cores/12 threads at 4 GHz using only 1.26 volts at full load (crunching)


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