# Best tools to stress test undervolting



## ivanosky (Sep 13, 2020)

Hello everyone. I have a Dell Inspiron 15 7559 with a Intel Core i5 6300 HQ and I have been using Throttlestop to undervolt the CPU for around 3 1/2 years. I achieved a stable undervolt of -125mV and kept the temperatures relatively lower, it used to go over 90 degrees without the undervolt,, with the undervolt and a cooling pad it was maxing out at around 80 degrees. Right now where I live there's higher heat than usual and the CPU temps have been getting a lot closer to 90 degrees, while I know that the max rated temperature this CPU can sustain is 100 degrees I don't feel too comfortable letting it get so hot, so I thought about increasing my undervolt. My question is, what are the best tools to stress test the CPU to check for stability? I've been using the TS Bench (1, 2 and 4 threads; 96M and 768M), Cinebench R20 and OCCT for synthetic tests and games that max my CPU like The Witcher 3 and Final Fantasy 15 for gaming tests. Any other tool you would recommend?
Thanks in advance.


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## DeathtoGnomes (Sep 13, 2020)

have you been using a laptop fan pad?


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## ivanosky (Sep 13, 2020)

DeathtoGnomes said:


> have you been using a laptop fan pad?


 Yes, I mentioned in the OP that I was using a cooling pad.


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## Voluman (Sep 13, 2020)

Aida stress test with fpu. 
Prime95 or intel burn test with avx if you are maximalist.
I like to use blender and the bmw scene. Or any videoencoding test.
And 7zip benchmark for memory testing, it is pretty quickly throw itself out if any setting not good.

But the most relevant, the programs you use generally, if those are working, you are good to go.


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## xman2007 (Sep 13, 2020)

Some fresh T.I.M would help you shave a few more degrees off it more than likely if it's around 4 years old and using the stock paste


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## ivanosky (Sep 13, 2020)

xman2007 said:


> Some fresh T.I.M would help you shave a few more degrees off it more than likely if it's around 4 years old and using the stock paste



I'll think about it. I'm not too comfortable taking out the heatsink to apply new thermal paste, but will have to do it eventually. I dropped another -10mV to the undervolt, reaching -135mV, I previously did -150mV which was stable in benchmarks, but crashed in The Witcher 3. That's why I'm asking about tools to stress test the undervolt. I'll also probably remove the slight overclock I have on the GPU (GTX 960M, +135 MHz) until the weather gets a bit cooler.


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## 27MaD (Sep 13, 2020)

I prefer Prime95, Small FTTs.


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## Caring1 (Sep 14, 2020)

You could try Intel's processor diagnostic tool which includes a stress test.








						Intel® Processor Diagnostic Tool
					

This download record installs the Intel® Processor Diagnostic Tool release 4.1.7.39, which is compatible with multiprocessor systems.




					downloadcenter.intel.com


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## DeathtoGnomes (Sep 14, 2020)

ivanosky said:


> Yes, I mentioned in the OP that I was using a cooling pad.


sorry missed that bit. I dont see the need for a stress test, what exactly are you looking for? I mean what kind of stability? during gaming only? you would want to use something like Heaven or 3DMark, but even then I dont see the need on your 4 year old system, no amount of testing will tell you anything different than what you already know. If you're worried about heat, ghettomod better airflow/cooling into your laptop.


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## ivanosky (Sep 14, 2020)

DeathtoGnomes said:


> sorry missed that bit. I dont see the need for a stress test, what exactly are you looking for? I mean what kind of stability? during gaming only? you would want to use something like Heaven or 3DMark, but even then I dont see the need on your 4 year old system, no amount of testing will tell you anything different than what you already know. If you're worried about heat, ghettomod better airflow/cooling into your laptop.



I intend to push my undervolt lower, and wanted some opinions on the best way to stress test it to ensure the system is stable. So far I reached -135mV, and can confirm that -150mV is not stable. Will try to reach -140mV or -145mV.


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## Valantar (Sep 14, 2020)

A bit unrelated to the topic - undervolting might be worthwhile despite this - but you really shouldn't worry about those thermals. The CPU has built in protection circuitry to avoid any type of thermal damage, and there is no evidence suggesting that the CPU takes any kind of damage from running at TJmax for extended periods of time - it'll simply throttle down to avoid going over the limit. (And the limit is obviously set lower than what the silicon could actually handle.) Just look at Apple's laptops: they run hot as all hell and throttle like there's no tomorrow, all to stay slim and quiet, yet they also have a well deserved reputation for longevity. (That obviously isn't to say that there aren't other laptops out there that last as long or even longer, they're just an easy example to use.) So while there are obviously other benefits to undervolting (better turbo, more battery life), don't worry about it if you aren't able to lower your thermals, at least as long as you aren't throttling and losing performance.


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## lsevald (Sep 14, 2020)

I got no experience with laptops, but an often overlooked issue with oc/undervolting is stability at idle, or rather when the CPU switches between idle and active state. I don't know how many times I've been happy with x hours of prime95 stability, only to get a BSOD/freeze when starting Chrome from an idle system. Increased Vcore, and looser LLC can be a friend here, as you can have higher Vcore at idle, that will lower as a function of CPU load. So when testing stability, I suggest taking a break and use your system normally as a part of the routine


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## Deleted member 193596 (Sep 14, 2020)

Prime95 is the only proper stability test for testing the basic cpu core stability.

just saw it with my 10600k.
IBT ran for 2 Hours with the "Maximum" stress level and passed.
then AIDA64 Cache,Core and FPU
and then realbench. 
everything passed without any issues.

15 seconds in Prime95 and i got a BSOD.


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## EarthDog (Sep 14, 2020)

WarTherapy1195 said:


> Prime95 is the only proper stability test for testing the basic cpu core stability.
> 
> just saw it with my 10600k.
> IBT ran for 2 Hours with the "Maximum" stress level and passed.
> ...


Funny,  if you ask anyone else, they will have a different story. 

Proper stability testing is finding the application that works best for your and your uses.


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## Deleted member 193596 (Sep 14, 2020)

EarthDog said:


> Funny,  if you ask anyone else, they will have a different story.
> 
> Proper stability testing is finding the application that works best for your and your uses.


i bet "anyone else" is not a person that had over 15 CPUs and around 10 different motherboards where every single chip over different architectures and manufacturers ( AMD/Intel) behaves exactly the same.

stable in everything... except prime = not stable.
my 3800x runs at 4.4 Ghz linpack for months if i want to. 
prime95 does not even run a single minute at 4.3

same with every single chip i have. 
it is stable in everything except prime.. you're probably fine but there will be a scenario where it is not stable because it has prime like loads for a moment. 

for example 5 Ghz all core runs everything except prime for a month now. 
a few days ago i bought 7 days to die and while creating the map it crashed and i had 4 cpu errors in HWInfo...
and this chip was stable in every existing stresstest with no time limitation.

after years of heavy overclocking and benching many different chips. 

Prime95 or nothing.


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## EarthDog (Sep 14, 2020)

WarTherapy1195 said:


> stable in everything... except prime = not stable.


If you say so, lol.

Stable for _your uses_ = stable. However people come about that is up to them. There are better and worse methods. For example, if I happen to run AIDA64 (for any of the literally over 100 CPUs I've had) and my system doesn't crash. It is stable for me and my uses.


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## Deleted member 193596 (Sep 14, 2020)

EarthDog said:


> If you say so, lol.
> 
> Stable for _your uses_ = stable. However people come about that is up to them. There are better and worse methods.



"your uses"?
do you run a oscilloscope attached to your cpu while using your PC and uninstall the programs that have the same transient dip as a P95 run in a random microsecond?

there is no "your uses" there is stable and not (fully) stable.

there will always be some kind of prime95 like transient dips in a certain moment and in completely random cases that can cause a bsod. that can simply be by loading a big resolution photo, starting a game or just copying files. even if it takes several weeks or even months.


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## EarthDog (Sep 14, 2020)

WarTherapy1195 said:


> "your uses"?
> do you run a oscilloscope attached to your cpu while using your PC and uninstall the programs that have the same transient dip as a P95 run in a random microsecond?
> 
> there is no "your uses" there is stable and not (fully) stable.
> ...


Yes, my uses. there is stable for me and, apparently, stable for you. Your mistaking me, and many others, for someone who cares about being more stable than I(we) ever need to be. I get your point... but, are you telling me that my system is NOT stable even though EVERYTHING I DO on it works and doesn't cause issues/BSOD? Good one. We'll have to agree to disagree on what it means to be stable.

For 99% of users though, so long as it is stable for how the PC is used, it can and will be considered stable.

If someone starts using my PC for something more stressful and it doesn't work, I'd have to go back to the drawing table.. But considering I can use AIDA64 cpu/fpu/cache and fpu only and my PC is stable for everything as light as gaming and as heavy as using Handbrake and rendering for a few hours, I'm not too worried.


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## M.R_KING (Sep 14, 2020)

and what about aida64???


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## ivanosky (Sep 14, 2020)

Valantar said:


> A bit unrelated to the topic - undervolting might be worthwhile despite this - but you really shouldn't worry about those thermals.



I know that the CPU can work normally up to 100 degrees and it will throttle before getting damaged, it's just that I feel a bit nervous seeing the temps over 90 degrees. When this happens I spend more time looking at the temps on the Rivatuner Statistics Server OSD and I stop enjoying the game I'm playing. I swapped my cooling pad for another one that has a bigger fan, that and dropping to -135mV lowered the temps by around 5 degrees. I'll try to reach -140mV and leave it at that.


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## EarthDog (Sep 14, 2020)

M.R_KING said:


> and what about aida64???


What about it? Who are you asking... 



ivanosky said:


> I know that the CPU can work normally up to 100 degrees and it will throttle before getting damaged, it's just that I feel a bit nervous seeing the temps over 90 degrees. When this happens I spend more time looking at the temps on the Rivatuner Statistics Server OSD and I stop enjoying the game I'm playing. I swapped my cooling pad for another one that has a bigger fan, that and dropping to -135mV lowered the temps by around 5 degrees. I'll try to reach -140mV and leave it at that.


You'll need to get over it. As he said, these throttle at 100C. There is a thermal shutoff a few/several C above that value which is the, 'oh shiza I'm going to be damaged unless...' threshold.


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## M.R_KING (Sep 14, 2020)

i'm asking 27mad he prefer Prime95, Small FTTs 

what about aida 64??


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## John Naylor (Sep 14, 2020)

Most of us got started w/ stress testing in the 90s when ou water cooling systems were either new products or user re-application of components from other sources.    As a novice some Guru suggested an utility to test something and that guy knew everything ... but that was 20 years ago and things change.   Today, testing with synthetics is not really an appropriate strategy.  What is the point or proving that yoiur system can do something it will never, ever be asked to do again ?   Why unnecessarily reduce yiur OC or decrease performance by undervolting based upon a load your system will never ever see ?   "Well if it's stable in everything but P95, it's not good enough?"  Why, ... if it will never, ever, ever see that type  load ?    If the goal to eek the best performance you can running loads your system might actually be exposed to ... or running loads it will never see ?   It like picking a CPU for your next build that has "more cores" when you don't use any applications that actually benefit from more cores.  

1  Would you test an new 500 pound engine hoist by  lifting 2000 pounds ?  It will never see that load.

2.  Would you test if your SUV could handle towing your new 450 pound SkiDoo / Trailer 12 miles to the beach (@ sea level) by towing a 12,000 pound trailer up and over the Rocky Mountains ?  It will never, ever see that load or that altitude ... or those slopes.

3.  Living in an area that sees significant snow and sleet, would you choose all season tires based only upon testing in only one weather condition ?

4.  Would you evaluate a potential baseball draft choice by only throwing him fast balls ?   What if he can't hit a curve ?  P95 is a 200 mph fastball.

Synthetics came into common usage when folks were testing the water cooling systems for adequacy and it became the holy grail for those aching to get their name on web site OC Leader Boards  The fact remains, it's a poor tool for "Real World" CPU Stability Testing.

a)  Most time an older version is run as  the newer versions w/ AVX and modern instruction sets can damage the CPU
b)  So the "Well it's not really stable unless it passes Prime 95" is kinda silly because if using the older version, it is not necessarily stable with modern instruction sets.
c)  You can have 24 hour stable P95 OCs fail in a multitasking benchmark like RoG Real Bench in 20 minutes.  Been there, done that.
d)  After you do the stability test , when is the next time you have a need to run P95 ?

There's a place for synthetics.   We use P95 on a new build to quickly bring CPU Temps up to levels we never will or want to see during the CPUs lifetime.   P95 allows us to cycle it up to 85+ and drop it to room temp 4-5 times to cure the TIM.   The laptop I'm typing from (custom built Clevo) has a slight overclock .  It has survived Furmark and runs fine with no undervolting.  Temps never break high 70s.   It doesn't use a laptop cooler... in fact, tried on on it's predecessor  and it blew out 2 of the USB ports (Note:  If you use a laptop cooler, plug it in to a USB hub with its own power supply).

Application based stress tests like RoG Real Bench will allow you to obtain higher performance for the life of your system, because you are not unnecessarily gimping performance to handle load conditions that it will never be exposed to.

a)  Put the CPU under a "real" application based load which is far greater than your laptop or system will ever see.
b)  It's a multitasking stress test which stesses the CPU in ways P95 is incapable and much more similar to what your system might, see in its lifetime
c)  It tests the CPU under different types of loads at the same time .... a far more challenging situation than 1 single load type.

In short:

1.  Stylish thin and light reduces battery life and cooling performance.   Pick a lappie with physical characteristics and component specs that match your needs.   Custom built recommended and cheaper.   These always have a key combo which lets you set fans to 100% when desired.

2  If you need a laptop cooler, use it with an external USB hub, do not connect to laptop.   Putting something under the back end of ya lappie whole using works wonders.    I use these cause I have a dozen of them lying around but a small strip of wood is fine.  



			Amazon.com : engineers scale
		


3.  Run RoG Real Bench Benchmark (8 minutes) watching temps with HWiNFO.   If no issues you can perhaps loosen up your undervolting and try again.  When you think you at the point you wanna be, run the RoG RB Stress test with the 50 of the - 75% amount of RAM (or 100% if ya like but 75 more realistic worse case) for 2 - 4 hours.


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## 27MaD (Sep 14, 2020)

M.R_KING said:


> i'm asking 27mad he prefer Prime95, Small FTTs
> 
> what about aida 64??


I really prefer Prime95 over any other softwares for RAM & CPU testing.


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## DeathtoGnomes (Sep 17, 2020)

EarthDog said:


> so long as it is stable for how the PC is used


This. This says it all.

OT/ was Prime95 even updated for Ryzen?


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## Ascaris (Sep 17, 2020)

ivanosky said:


> My question is, what are the best tools to stress test the CPU to check for stability? I've been using the TS Bench (1, 2 and 4 threads; 96M and 768M), Cinebench R20 and OCCT for synthetic tests and games that max my CPU like The Witcher 3 and Final Fantasy 15 for gaming tests. Any other tool you would recommend?
> Thanks in advance.



When I was overclocking my desktop (Sandy i5) years ago, I found that OCCT was just as effective in provoking BSODs as Prime95, and had nice graphs too, so that was what I used. My relatively low-volt OC was not "stable" in my way of thinking until it had passed 24 hours of OCCT (on the maximum stress setting, whatever that was. It's been a long time). That same CPU is still trucking, years later... I am using it now to write this!

More recently, I undervolted my Dell G3 (i7-8750H), and since I do not use Windows anymore, I went back to Prime95, which has a Linux version (though it has no GUI). I didn't demand a full 24 hours, but it did go overnight plus a few hours. I also ran it for ~24h running Folding@Home a couple of times, running actual tasks until completion, with a custom setting of 6 threads (HT off), and that's a workload that should be quite similar to Prime95.

With the -150mv undervolt and Thermal Grizzly TIM (I nickel plated the heat sink first using an inexpensive kit [$50] to keep the gallium from migrating into the copper), it does not thermal throttle at all completely maxed out with P95 or F@H. It does power throttle to get under the 45w cap... I used the undervolting tool to let it run at 45w (the short power limit) indefinitely, but it would not let me raise that cap. No matter what I entered, it throttled at 45w.  It still managed to get up to (or very close to) the six-core turbo boost cap, which I think is 3.9 GHz.

Running full-bore on all six cores, core temps remained in the high 70s C (ambient temp about 78F, no laptop cooling pad, just a set of "laptop lifts" rubber feet on the back).  There's a little headroom left in there for the GPU during gaming sessions (which would not push the CPU nearly that hard).

The GPU is a lot better at doing the folding, but in this case, I was testing thermal and stability as well as doing the folding tasks, so I only used the CPU. The GPU is far faster per watt of energy consumed, of course.


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## Final_Fighter (Sep 17, 2020)

here is a simple set of tests:

1: run memtest for 2 hours. have at least 80 percent of your ram being used.

2: run cinebench r20 3 times back to back. 

3: run p95, with small ffts for 2 hours.

Usually if all the tests listed above pass than you system is good to go. now, the above tests dont stress the gpu. usually the best way to do that is to just game on it.


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## kn00tcn (Sep 17, 2020)

ivanosky said:


> I know that the CPU can work normally up to 100 degrees and it will throttle before getting damaged, it's just that I feel a bit nervous seeing the temps over 90 degrees. When this happens I spend more time looking at the temps on the Rivatuner Statistics Server OSD and I stop enjoying the game I'm playing. I swapped my cooling pad for another one that has a bigger fan, that and dropping to -135mV lowered the temps by around 5 degrees. I'll try to reach -140mV and leave it at that.


why do you feel a difference between 85 vs 95? it's too hot for humans either way, metals or plastics have completely different points on the scale

does your laptop have a button or software for maximum fan speed? because most or almost all automatic fan modes that manufacturers provide do not trigger max fan speed until after 90 degrees (if at all), resulting in higher temps than potentially possible

can you try setting windows power options to 99% max cpu instead of 100%? this might reduce or disable turbo states, which could reduce temps/volts automatically, the performance might still be acceptable


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