Pros and cons of Undervolting, And how much should i do it for my pc?

Noodles_fluffy

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Nov 10, 2016
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Here is my pc specs, if you need that to determine how much I should do it. I heard that you keep lowering it til you crash, but im terrified with that because i've been going through some difficulties with my pc lately.

Processor Intel(R) Core(TM) i7-4700MQ CPU @ 2.40GHz
Video Card NVIDIA GeForce GTX 770M
Video Card #2 Intel(R) HD Graphics 4600
RAM 16 GB
Operating System Microsoft Windows 10 (build 14393), 64-bit
The laptop is a Toshiba Qosmio x75A if you need to look it up.
 

Noodles_fluffy

Commendable
Nov 10, 2016
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1,510


Yeah actually. I also read that Toshiba does a horrible job with the thermal paste but I don't have any at the moment so the undervolting is a temp fix, at least until I attempt to open the laptop and find the thermal paste. Im actually kind of new to computers so the thought of having to open it up and mess around with stuff scares me and i can't find any guides for my specific computer.

 

rhysiam

Honorable
Mar 24, 2013
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Also just to add, it's a very bad idea to start messing with under or overclocking if your system is unstable to begin with. When you say you've hit "some difficulties" lately, what does that mean?

Messing with voltages and frequency requires a systematic approaching: unless you really know what you're doing, the best approach is to change 1 setting then test extensively, change again -> more testing. That way as soon as you hit an issue, you know exactly which setting caused the problem. If the computer is unreliable or unstable to begin with, you're in a mess because you'll have no way to know where the issue is coming from.

In terms of a general response, the only real "con" for undervolting is potential stability issues if you push voltages down too low. As a basic principle, higher voltages make it possible to achieve higher frequencies (= clock speed = performance), but at the cost of power and heat. If a voltage is too low for the frequency the CPU/GPU is trying to run, transistors won't be able to switch quickly enough and you'll get errors, BSODs, lockups, etc. Just to be clear, these issues caused by insufficient voltage will NOT physically damage your processor, they just cause it to not return the correct values and your system doesn't cope with this (thus crashes, freezes, BSOD, graphical glitches, etc). So ideally, CPUs and GPUs will run at the lowest possible voltage for their given frequency (thus less heat and power), but with just enough voltage to keep everything completely stable. The issue for AMD, Intel, Nvidia, etc, is that no two processors behave identically, that's the silicone lottery, some will run higher frequencies at low voltages, others not so much. While all processors are tested, it doesn't make financial sense to spend hours and hours stress testing each and every chip to determine its particular eccentricities, and they can't afford to cut the voltage too low and release a chip that might possibly error out under particular workloads. So, they have to be fairly conservative with the voltages they set. Because of that, if you have a system that supports it and you're prepared to do the careful testing yourself, you can often find a lower stable voltage than that set by the manufacturer.

So yeah - TLDR, you're trading off lower heat and power draw for potential instability and lockups.

The issue with undervolting is that no amount of stress testing can ever guarantee you 100% stability. Case in point, I got to what I thought was a very stable OC on my GPU for 8 months. Played loads of different games with no issues whatsoever. But then I got Witcher 3 and it would crash within 5 minutes every time. Bumped up the voltage again slightly and it was fine. I don't know why Witcher 3 on my particular card seemed to need just that little bit more voltage than anything else, but it did. People who undervolt will sometimes hit the same thing - you think it's stable until you find a particular workload that undoes it. But if your system supports undervolting and you're prepared to accept the potential instability and having to adjust things in future, there's not really any other drawbacks.
 

Unolocogringo

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Dec 31, 2007
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^+1 to the above.
Even though it is a very easy and simple thing to do. To get it right takes time and patience. you cant look at a you tube video and set your processor or video card to the same settings and expect the same results. Every piece of silicone is different.
You have to keep track of settings and do lots of stress testing.

I overclock everything to its limit of complete stability and then put it to work Folding. Which requires Complete, absolute stability.
But it can take several days to find that point and then a complete 48hour stress test to see if my settings are good.
If it passes, it can then start Folding.
 

Noodles_fluffy

Commendable
Nov 10, 2016
7
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1,510


Honestly, when i said problems, it wasn't that the pc was unstable. I was just basically freaking out over nothing. The thing is, since my computer apparently comes with horrible thermal paste and i don't want to open it up and fix it right now, i need to lower temps so that it will stop my framerate from lowering due to higher temps.
 

rhysiam

Honorable
Mar 24, 2013
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Well in that case, undervolting is not a bad idea if you're willing to put the time in to do the stress testing. If you're not willing to replace the thermal paste (which is totally understandable and probably voids warranty if you still have it), the only other thing you should do is make sure there's no dust build up anywhere. A can of compressed air might not go astray.

It sounds like it has a metal body which might dissipate some of the heat, so it's possible one of those laptop coolers *might* make a bit of a difference for extended gaming sessions.

But yeah, undervolting is certainly worth a shot.