Does undervolting makes your cpu hotter? - General Questions and Answers

Recently I was in an argument with a forum member.
He claims that undervolting will make cpu go overheat instead.
Is the statement true or false?

undervolting doesnot overheat as the processor will not get that much amoumt of voltage to go to temperature that are away from normal. just apply physics here. no over heating will happen. but your device can end up in bootloops as the proceasor will not get the power to go to higher hertz to perform operations to open and loade android platform

Related

[Q] What's the best way to find how overclockable your phone is?

It seems like every phone can handle a different clock speed, is there is a tried and true way to find the optimal clock speed for your phone?
No as u say every phone acts on hes own so i dont think there is any software for this ( optimal overclock) but there is software for ocing it easy like setcpu or nstools... you can oc your cpu by raising it, and using it with multitasking and if it doesnt reboot in hour or two of heavy usage then go step higher. When it reboots try with step or two higher voltages and so on until you get highest cpu with moded voltages (not more than 2 steps) stable with no reboots. Ofc i wouldnt recommend this as you are not getting anything special from it and you risk your phone... btw optimal cpu speed is its own stock speed that is just pure logic xd
Though there is no agreed upon definition, to me the optimal cpu speed is not the stock speed, the stock speed is the standard safe speed. When a CPU is manufactured it invariably has defects, the number of defects dictates the speed at which it can run. For example, when they manufacture the i5 and the i7 they probably just take defective i7 chips and turn off two cores and call it an i5. (I don't know if they actually do this with the i5 and i7 but it's been common practice with just about every processor in the past.)
I guess I should use a different term like, maximum safe speed.
Trial and error is the best way to my knowledge, haven't heard of any phone apps adjusting clocks on the fly based on temp, inaccuracies, etc, like on a computer. You can feel the temp of the phone and it'll reboot at the smallest sign of instability, just don't set test profiles to set on boot.
And what you say is correct. Processes with similar imperfections are grouped, tested and sold under a given name with the benchmark being stock frequency and voltages. Common practice and very often you get some chips you can over clock til it expands out of its bracket and others which fail at everything but stock.

my philosophy on overclocking

Seems like some recurring discussion in past threads:
1 - why should we even bother overclocking if we’re not a gamer.
2 - won’t we damage our device with overclocking.
I haven’t seen definitive answers posted anywhere, and I certainly don’t have one.
Maybe in that case (I have no definitive answer), I should probably just keep my mouth shut.
It may be the case, if so let me know.
For whatever reason, I have some strong opinions and I feel it would be useful to share my opinions and the reasons I have formed those opinions.
Take them or leave them or add to them... up to you.
Point out to me if you think I am grossly mistaken.
1 - why should we even bother overclocking if we’re not a gamer.
Click to expand...
Click to collapse
There is constant tradeoff between battery and performance.
Underclocking will help you save battery. How low you want to underclock depends on what you can tolerate.
But what you can tolerate depends on your user experience, which can be dramatically impacted by use of overclocking at other times.
The perfect example for me is a program which is slow to start up. In my case it is Memento database with 1000+ records, takes a long time to read in (I think the program does some sorting every time it opens). That is a minor annoyance. If I were to underclock it will start even slower, I’m going to get impatient and set my speed back up.
But think about this:
1 - Using Tasker you can apply cpu profiles upon application launch and remove them after a predetermined length of time. I can give the program a blast of 1600M-hz when it starts, then set it back where it was after predetermined period (for example 10 seconds).
2 – Setcpu is not quite as flexible as tasker in this regard. With setcpu we can create a profile to occur when we launch the program like Memento, but we just can’t incorproate a time delay into the logic (it will stay on the higher profile as long as the program runs in the foreground).
3 - There may be circumstances where this setcpu behavior is what you want... it will give you faster response whenever the program is in the foreground, and will yield to lower priority profiles whenever the program goes to the backghround.
(I haven’t investigated how to make make Tasker and setcpu play nicely together yet).
So, if you speed up the things that cause noticeable delay for only a short time, or particular applications which seem to run slow then you can probably be more satisfied with your underclock in the other times. In the overall picture, I think the overclock capability can ironically be used as part of a strategy to save battery (unless you just like overclocking just to see things zip accross your desktop and menu’s pop in and out faster than you can blink, I’m starting to get spoiled with that behavior on my phone in its new configuration, partially from overclock..I’m sure others get even better in their configuations..).
2 - won’t we damage our device with overclocking.
Click to expand...
Click to collapse
On this I would say no, as long as you are careful about not running it in conditions that create high temperature. .
(you may have stability problems as you guys know, an entirely different subject).
The physics of the damage are all related to temperature. There are many variables affecting temperature that the designer is unaware of and so he builds in margin for the worst cause unknown future occurence (he has to consider maybe phone will be in desert with 100F ambient, and on the charger, while the user tries some heavy surfing with gps, all at the same time, so he limits cpu to 1200Mhz).
We on the other hand know what are the conditions of our phone and what it’s likely to see and what it’s doing at any given time, and setcpu provides additional ability to monitor and adjust.
Here are example setcpu profiles I came up with to protect myself from damaging temperatures (Zen's kernel A/1600)
Priority 100: If batter temperature > 50C (122F),establish conservative governor 100-400Mhz
Priority 90: If batter temperature > 45C (113F),establish conservative governor 100-800Mhz
Priority 80: If battery temperature > 40C (104F), establish conservative governor 100-1200Mhz (in the event I was overclocking, this profile will stop it when battery temp exceeds 40C, all other profiles that may invoke overclocking are lower priority than 80).
This is just from judgement, knowing that I’m normally < 104F battery temp during light use and don’t want to overclock when I’m outside that normal light use zone. Some further curtailment of cpu max frequency occurs as battery temperature climbs above that. (which I would not have even had the benefit of if I were casual user with no overclocking and no setcpu).
As long as you’re limiting temperature, you should not be worried about damage imo. By the way, of course overclocking is not the only thing to affect temperature: things like phone case (thermal insulation), charging, gps, heavy use etc all have an effect. I'm not quite sure why sometime cpu overclocking gets singled out in a dangerous category all its own without any discussion of other things that affect tempertaure.
In fairness, you may point out that what we monitor is battery temperature and not the same thing as cpu temperature. It’s a good point. Increase in heat generated at the cpu causes more of an increase in temperature at the cpu then it does at the battery. But it's question of how much different. there's a matter of how much. Why do you think it is that Samsung didn’t give us cpu temperature indication? I think because they knew battery temperature is close enough. Even on newer flagship Behemoth Samsung Note, I’ve read you still only get battery temperature, no cpu temperature. If cpu temperature was that much different, they surely would have provided a separate indication of cpu temperature (cpu is after all a much more critical component than replaceable battery).
And why should we expect battery temperature to be representative of cpu temperature on our phone, when the same is not true on a pc? I think I can answer that:
* PC has things all spread out. There is air flowing through. The air picks up heat from each component from heat sinks by convection. The component temperatures are not tightly coupled together.
* Phone (in contrast to pc) has everything compact inside one itsy bitsy case. There is no air flowing through. That means heat transfer inside the phone is not by convection but by conduction. For most effective conduction, all components are attached with high thermal-conductivity path to the phone structure and the exterior surface of the phone. The heat transfer from phone to ambient is primarily convection. So we have effective heat transfer (conduction) among the components of the phone and less- effective heat transfer (from phone to environment). It tends to tell us that there will not be big difference in temperature among phone components. The big temperature difference that occurs is between the phone and the ambient air.
I don't have access to a phone which has both cpu and battery temperature indicators. If someone does, it would be interesting to hear how close those two temperatures follow each other.
===================================================================================
Edited to add: searching other threads suggests there can maybe be a substantial differencebetween cpu temperature and battery temperature. That makes me a little less certain. At least we can use battery temperature as a gross indicator that the cpu isn't seeing excessive extra heat from other non-cpu sources while we're overclocking it. Certainly having profiles in place to limit overclocking when battery temperature is high can only help protect us. But is it a false sense of security which can lead us astray? I dunno. I have already done a stability test at 1600 for quite awhile and there's no damage in sight, so if there is any damage potential, then it is only an accumulation over time. I don't plan on leaving Fmax at 1600 all the time anyway, since it would kill the battery. My planned strategy reserves the 1600 overclock for occasional playing around, and boosts when I need them like like my Memento database. My gut says that approach is just fine. Interested in hearing any other thoughts, experiences, links that may shed light.

[Q] A700 CPU Clockspeeds?

Hello,
I've a question regarding clockspeeds. Since yesterday i rooted my tab, as an early adaptor i experienced the lagging, heat failures etc. Since the JB update i've the feeling that the cpu doesn't run on max speed, also scaling the other cpu's is not as fast...
I downloaded several cpu monitoring apps, i found out my cpu never reaches 1.4Ghz. Max is 1,3Ghz, i don't know of thats for real or a bug in the monitoring code. But several apps have showed this, ex system tuner, also i found out that almost never the fourth cpu comes on. I'm not an excesif gamer, but for the test i played asphalt 7 and nfs shift.
Do you guys have an idea how to solve/tune? I already flashed the Vorbeth GPU OC (Thanks!:good but i wasn't able to find any more kernels or CPU mods.
To me its very very annoying that have a quad, but scaling very very conservative (I don't care about battery), i just want to ramp up and use all the cpu's hence i'm a multitasker.
Overall, i've the "feeling" that the heat issues are solved by using a very very conservative governer and not scaling max. Maybe i'm totally wrong, and i would be happy to hear that. Right now i feel kinda screwed.. by acer.
edit: Sorry for posting in general, i realize i've should post in QA
power saving level "balanced" is 1.3ghz, "High Performance" is 1.4ghz. It got introduced with an update. So your monitoring app is correct.
It could be possible to clock the A700 to 1.5ghz, but I wouldn't go higher since it's already getting hot enough on high CPU usage.
nex86 said:
power saving level "balanced" is 1.3ghz, "High Performance" is 1.4ghz. It got introduced with an update. So your monitoring app is correct.
It could be possible to clock the A700 to 1.5ghz, but I wouldn't go higher since it's already getting hot enough on high CPU usage.
Click to expand...
Click to collapse
Thanks, however i've always turned high performance on. I forgot to mention, but aslo during testing.

[GUIDE] [Initial incomplete] Galaxy S4 CPU/GPU overclocking/undervolting

What is overclocking?
Overclocking is the process of making a computer or component operate faster than the clock frequency specified by the manufacturer by modifying system parameters. One of the most important techniques is running at a higher clock rate (more clock cycles per second; hence the name "overclocking"), but other parameters, such as CPU multiplier and memory timings, can also be changed and would be considered to be overclocking. Operating voltages may also be changed (increased), which can increase the speed at which operation remains stable. Most overclocking techniques increase power consumption, generating more heat, which must be dispersed if the chip is to remain operational.
Advantage:
Higher performance in games, encoding, video editing applications, and system tasks at no additional expense, but with increased electrical power consumption. Overclocking can extend the useful life of older equipment. Adding noticible response time for multitasking and powerhungry applications and games.
Disadvantages:
Overclocking if it's not done with moderate rate can be very risky and potentialy might permanantly damage your device's hardware, plus it can cause a slight battery drain. If it's done correctly then you're good to proceed.
Undervolting :
Undervolting is reducing the voltage of a component, usually the processor, reducing the voltages of each step less than the original stock voltages.
Advantages:
Increase of Battery life.
The heat that come from the processor reduces.
Disadvantages:
Undervolting if it's applied correctly then it's good, Hard undervolting might make the device unstable and potentily will lead to bootloops and freezes.
CPU
Maximum clock that could be applied on The Galaxy S4 is XXXXmhz and the minimum is XXX mhz . I will add the stock clock values as soon as possible.
More to come asap !
SERIOUSLY?
A guide about overclocking when you don't even know what CPU the specific models will be getting?
AndreiLux said:
SERIOUSLY?
A guide about overclocking when you don't even know what CPU the specific models will be getting?
Click to expand...
Click to collapse
I as well, think that this is a bit strange...
AndreiLux said:
SERIOUSLY?
A guide about overclocking when you don't even know what CPU the specific models will be getting?
Click to expand...
Click to collapse
and probably the S600 version will not be OCable its already has throttling problem due overheating ( + its an OCed version of S4 pro )
Weird thread
sent from an Galaxy s3 GT I9300
Running perseus kernel 33.1 , XELLA 4.1.2 leaked build
forum.xda-developers.com/showthread.php?t=1784401
Dont click,you might regret , I won't be responsible if you brick ur head
jus sawed this guide tosee whats safe minimum voltage and other stuff! better to change title or a how to (i already know btw )
lol this is horrible! where's guide to udenervolt? i also underclaockd m cpu to 1GHZ that feels a lot lot colder and still freaking fast! even think more stable! also i wannt to underclaock the GPU too and also udnervolt it anyone knows how? i got i9500 octa

Reduce heat due to high CPU frequency?

Hello, is there a way to reduce the heat due to high CPU frequency? In fact, when I play games such as Real Racing 3, in order to maximize my phone's potential as it has quad core, I usually set my CPU to maximum frequency (1.8GHz). However, l discover that the CPU drops back to 1GHz or lower, after about 10 minutes of gaming. In the beginning, I thought that it was a bug, but consulting someone in this forum, I discovered that the drop is part of the CPU protection feature. I appreciate this kind of safety feature but it will be boring that you can only enjoy a short 10 minutes of gaming before the phone heats up like a kettle. So, here is the question, is there a way in order to reduce the heat due to high CPU frequency? Will undervolting (UV) be recommended? Thanks.
Heat is generated as a byproduct of electical risistance... You'll have to exuse the bad spelling till I fix it...
1. under volting will reduse the electrons that are alowed to flow, thus reduceing the heat genorated, and it will also reduse your devices' performance.
2. A heat sync will reduce heat if the flat part is placed where the processor is. I ripped one out of an old copmuter and set my phone on it when modum tethering when playing online games and it works well. But not so comphotable when actualy using the device as the metal flanges coming off the other side of the heatsink are pokey.
3. A cpu govener change is the most likely solution to your problem of auto throteling and ramping of your devices' cpu friquancy. There are guides and info kicking around that using a google search like this:
cpu govener site:www.xda-developers.com
Will result in helpful reading matierial. I'd sugest looking at a program like rom tool box that will alow you to set up profiles that triger diferent cpu speeds and govenars bassed off of what your device is doing; such as when the screen is on, max frequancy=max, govenar=smartassV2 and; when the screen is off, max frequancy=50% of max, govenar=conservitive.
4. When all else is not good enough and you've gathered some info on how your device handles different govenars; then build your own. From what I've been reading its not so diffacult to tell your device exsactly how to behave in every way.
Hope some of it helps. And if you need some help with finding spisific sorces of info that I've hinted at, say something and I'll add some links when I spell corect this.
Sent from either my SPH-D700 or myTouch3Gs
Debian Kit Install guide for all android devices that I'm writing:
http://forum.xda-developers.com/showthread.php?t=2240397
Or
https://docs.google.com/document/d/1ssVeIhdBuuy8CtpBP1lWgUkG6fR6oHxP20ToYPPw6zI/edit?usp=drive_web

Categories

Resources