# Underclocking/undervolting for energy savings?



## PaulieG (Apr 7, 2021)

I'm sure I knew the answer to this a long time ago, but my memory isn't awesome these days. Does anyone underclock/undervolt their processors for power savings while running WCG? I ask because right now, I have a 5600x and 10850k running at home, and an i7 laptop running at my wife's office. I'm about to add a second 10850k and a 5900x at home this coming weekend. So, naturally with running so many systems at home, I'm worried about the electric bill, especially living in the south with hot months coming and air conditioning soon to be running non-stop. I'd appreciate any advise from anyone underclocking/undervolting. I'm wondering if if doing so creates significant savings.


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## Shrek (Apr 7, 2021)

Don't modern CPUs auto underclock/undervolt?


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## PaulieG (Apr 7, 2021)

Andy Shiekh said:


> Don't modern CPUs auto underclock/undervolt?


I'm looking at fixed clocks/cpu voltage beyond stock to lower energy consumption for cost savings and keep processors as cool as possible for longevity.


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## nguyen (Apr 7, 2021)

PaulieG said:


> I'm looking at fixed clocks/cpu voltage beyond stock to lower energy consumption for cost savings and keep processors as cool as possible for longevity.



Well for AMD use the curve optimizer and set a lower TDP will undervolt your CPU while keeping the core clocks.
For Intel 10th gen, we have the excellent ThrottleStop sofware for undervolting both your 10850K and the i7 laptop.


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## GerKNG (Apr 7, 2021)

as long as you don't render 24/7 at 5.2 Ghz all Core.. saving 30 watts in Prime95 is completely pointless.


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## WatEagle (Apr 7, 2021)

PaulieG said:


> I'm looking at fixed clocks/cpu voltage beyond stock to lower energy consumption for cost savings and keep processors as cool as possible for longevity.


for AMD enable PBO and set a lower PPT, if for example is 105w you can try maybe 80, it should auto regulate


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## Shrek (Apr 7, 2021)

Related but a little off topic

I understand that they sometimes run MOSFETS in power supplies intentionally hot (by limiting cooling) as this makes them more efficient. I am not suggesting this for a CPU, but maybe a high efficiency power supply if one is concerned about electrical consumption.


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## PaulieG (Apr 7, 2021)

nguyen said:


> Well for AMD use the curve optimizer and set a lower TDP will undervolt your CPU while keeping the core clocks.
> For Intel 10th gen, we have the excellent ThrottleStop sofware for undervolting both your 10850K and the i7 laptop.


I've used PBO and curve optimizer plenty. However, I've found that both my 3600x and 5600x ran cooler and more stable with the lowest possible fixed voltages.


WatEagle said:


> for AMD enable PBO and set a lower PPT, if for example is 105w you can try maybe 80, it should auto regulate


I hadn't tried setting a lower PPT. I may try that on the 5900x. Overall, I'm way more worried about my 2 10850k's. They have a high power draw and they run hot.


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## WatEagle (Apr 7, 2021)

Andy Shiekh said:


> but maybe a high efficiency power supply if one is concerned about electrical consumption.


this is also a good suggestion if he has spare money



PaulieG said:


> I've found that both my 3600x and 5600x ran cooler and more stable with the lowest possible fixed voltages.


fixed voltage with ryzen isn't always a good thing, for me it's better to let them auto manage. The only thing it's worth playing is ram if you want more performance and PBO to get marginal gains or in this case lower consumption limiting the PPT


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## PaulieG (Apr 7, 2021)

WatEagle said:


> this is also a good suggestion if he has spare money
> 
> 
> fixed voltage with ryzen isn't always a good thing, for me it's better to let them auto manage. The only thing it's worth playing is ram if you want more performance and PBO to get marginal gains or in this case lower consumption limiting the PPT


I spent weeks testing fixed vs. PBO. Hours and hours. My conclusion are both are fine, but if you have a good chip that will run a really low vcore at stock, performance will be similar but the fixed frequencies and voltages resulted in significantly lower temps, which is what I'm looking for with crunching.


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## Shrek (Apr 7, 2021)

For me it depends; if one's work is mission critical one can't afford any crashes a low voltage might imply.


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## PaulieG (Apr 7, 2021)

Andy Shiekh said:


> Related but a little off topic
> 
> I understand that they sometimes run MOSFETS in power supplies intentionally hot (by limiting cooling) as this makes them more efficient. I am not suggesting this for a CPU, but maybe a high efficiency power supply if one is concerned about electrical consumption.





Andy Shiekh said:


> For me it depends; if one's work is mission critical one can't afford any crashes a low voltage might imply.


I never buy garbage PSU's. The worst of the 4 psu's I own by a long shot is an Enermax Marblebron 650w Bronze. My other 4 psu's are all well rated gold models. Just looking at other ways to limit power consumption if I'm running several crunchers 24/7.


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## Shrek (Apr 7, 2021)

PaulieG said:


> I never buy garbage PSU's. The worst of the 4 psu's I own by a long shot is an Enermax Marblebron 650w Bronze. My other 4 psu's are all well rated gold models. Just looking at other ways to limit power consumption if I'm running several crunchers 24/7.


Put them in a room without air-conditioning.

I tend to recap my power supplies so they can take the Summer heat.


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## KLiKzg (Apr 13, 2021)

Personally, I would not go with undervolting to consume less power. Problems with issues at booting, cold start ups, overheating...you might end up with invalid results for all your work on WCG.

But there are things you can do, off course:

Turn OFF Turbo option in BIOS. That way your CPU will only work up to 100% of designed speed.
Your 10850k for example has Turbo from 100% 3,6GHz to 144% of 5,2 GHz - data from here.
If you can't do that, then you can setup in Windows to have you CPUs run up to 99%.
Control Panel -> Power Options -> Change plan settings -> Change advanced power settings -> Processor power management -> Maximum processor state = set on 99%
After that, processor will never go into Turbo.
Use software option for thermal management, suggestion is to use FREE version of Tthrottle.
This software I use on all my Windows based machines & have been running it for over 5 years. For Xeons I use up to 85% of Tjunc, for normal CPUs & AMD up to 75% - this is for desktops. As for laptops, it depends which firm is it? If it's some 3rd grade laptop firm (HP included) I don't go over 60% of Tjunc, for better ones I go with 75~80% of Tjunc (Lenovo, Fujitsu, Toshiba) & only some DELL laptops I push to 85% of Tjunc.
Hope it's useful & enjoy the summer.


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## phill (Apr 30, 2021)

I just limit the vcore the CPU has.  My 3900X runs at 1.15Vcore instead of the 1.4 or whatever it might do under a normal load.  Before on air cooling it would be running about the 1.0vcore (did get it down to 0.9vcore but then bios update on the board, meant 1.0v seemed the lowest I could go...)  Temps for air cooling about the 50 to 60C max load temps...

Now with water cooling, I run slightly higher vcore but still massively limit it.  I don't need it running flat out, just running comfortable and easy on the temps.  I tried running the water loop on the CPU when I had it set to 1.0vcore and it was barely hitting past 40C under all core load...  I've not been with Intel for a little while but I'd try the same thing again with that sort of CPU as well.  

Grab yourself a wattage meter if you haven't already and see what the different settings you use, do to the power consumption...  You'll be surprised


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## PaulieG (Apr 30, 2021)

phill said:


> I just limit the vcore the CPU has.  My 3900X runs at 1.15Vcore instead of the 1.4 or whatever it might do under a normal load.  Before on air cooling it would be running about the 1.0vcore (did get it down to 0.9vcore but then bios update on the board, meant 1.0v seemed the lowest I could go...)  Temps for air cooling about the 50 to 60C max load temps...
> 
> Now with water cooling, I run slightly higher vcore but still massively limit it.  I don't need it running flat out, just running comfortable and easy on the temps.  I tried running the water loop on the CPU when I had it set to 1.0vcore and it was barely hitting past 40C under all core load...  I've not been with Intel for a little while but I'd try the same thing again with that sort of CPU as well.
> 
> Grab yourself a wattage meter if you haven't already and see what the different settings you use, do to the power consumption...  You'll be surprised


Yeah, this is pretty much what I ended up doing. Just apply the rules I've known forever instead of looking for some kind of magical WCG specific answer. All my crunching systems are now slightly underclocked, undervolted, with all of them under water.


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## phill (May 5, 2021)

PaulieG said:


> Yeah, this is pretty much what I ended up doing. Just apply the rules I've known forever instead of looking for some kind of magical WCG specific answer. All my crunching systems are now slightly underclocked, undervolted, with all of them under water.


Best way I find    Air or water isn't such an issue but good cooling is a must if your running them 247 I feel    No point running them at 80C when you can knock it back a few MHz and take away some of the volts and get it running at 50 to 60C


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