Question S21 Ultra Exynos Heating Problem

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maharoof

Senior Member
Sep 5, 2013
60
10
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Samsung Galaxy S21 Ultra
Hlo guys, Hope you all are doing well.

I bought an S21 Ultra (Exynos) yesterday and it seems to be running hot even during normal usage. It heats up while I charge it (with a 33W Xiaomi charger) and it heats up even more (goes upto 43°C) while I am on a video call. I'm a little bit worried. Is this a faulty unit or just a software issue? Please help me out guys.
 

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Hlo guys, Hope you all are doing well.

I bought an S21 Ultra (Exynos) yesterday and it seems to be running hot even during normal usage. It heats up while I charge it (with a 33W Xiaomi charger) and it heats up even more (goes upto 43°C) while I am on a video call. I'm a little bit worried. Is this a faulty unit or just a software issue? Please help me out guys.
It will do that for a few days. I had the same experience on the first 2-3 days. But the heating issue went away after that. It will still heat up occasionally (just like any other computer) and especially when you do anything involving the camera. All the new apps are constantly writing info, building cache, etc - this should ease off once the initial intense activity has completed. Some heating is bound to happen when charging too.

The only things I would recommend changing for now are: If you don't use 5G or have poor coverage in your area, turn off 5G scanning from Connections setting. This seemed to help me with battery as well as heating. And FHD+ instead of WQHD+ resolution (at least till the heating issue is gone, and then you can play around with settings and see what you like)

My advice would be to just wait for a few days before doing anything drastic or trying to modify stock firmware. If not better by the end of the week, you can explore other options. The phone is just one day old. Just give the software some time to settle.
 
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tim84us

Senior Member
Mar 12, 2013
530
208
unfortunately thats just the way it is :(
am having the EXACT same issues and i had the phone since Feb so - not something that will go away unless Samsung fixes it
 
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maharoof

Senior Member
Sep 5, 2013
60
10
28
Samsung Galaxy S21 Ultra
It will do that for a few days. I had the same experience on the first 2-3 days. But the heating issue went away after that. It will still heat up occasionally (just like any other compluter) especially when you do anything involving the camera. All the new apps are comstantly writing info, building cache, etc - this should ease off once the initial intense activity has completed. Some heating is bound to happen when charging too.

The only things I would recommend changing for now are: If you don't use 5G or have poor coverage in your area, turn off 5G scanning from Connections setting. This seemed to help me with battery as well as heating. And FHD+ instead of WQHD+ resolution (at least till the heating issue is gone, and then you can play around with settings and see what you like)

My advice would be to just wait for a few days before doing anything drastic or trying to modify stock firmware. If not better by the end of the week, you can explore other options. The phone is just one day old. Just give the software some time to settle.
That's comforting to hear😇. Let me monitor it for another week. Should I continue using the 33W charger? Is S21 ultra capable of handling it? Or should I just buy the Samsung 25W charger? Thanks for the reply dude.
 
That's comforting to hear😇. Let me monitor it for another week. Should I continue using the 33W charger? Is S21 ultra capable of handling it? Or should I just buy the Samsung 25W charger? Thanks for the reply dude.
I haven't used the Mi charger. Tried with an old warp charger from OnePlus just for kicks and it doesnt super-fast charge the S21U. But that's becasue the propreitary fast charging standards used by different manufacturers are often incompatible.

After some research, I've found that the S21 ultra will not draw any more than 25 Watts of power (even if you use the Samsung original 45W charger). And even that 25W will work with only with a PPS (Programmable Power Supply) charger (USB C to C PPS) - like the 25W Official Samsung charger. There are a few 3rd party maufacturers that make PPS chargers, but I haven't used any of them. I just went ahead and bought the Samsung one, as there was a good discount on it.

Any other charger you use will only work as a slow charger, or a fast charger (15W max) at best if it supports Qualcomm Quick Charge (QC3) standard. For 25W Super-fast charging (it's anything but super-fast, but that's what Samsung insists on calling it) you need a PPS charger, and I would recommend going with the original 25W Samsung charger.
 
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maharoof

Senior Member
Sep 5, 2013
60
10
28
Samsung Galaxy S21 Ultra
I haven't used the Mi charger. Tried with an old warp charger from OnePlus just for kicks and it doesnt super-fast charge the S21U. But that's becasue the propreitary fast charging standards used by different manufacturers are often incompatible.

After some research, I've found that the S21 ultra will not draw any more than 25 Watts of power (even if you use the Samsung original 45W charger). And even that 25W will work with only with a PPS (Programmable Power Supply) charger (USB C to C PPS) - like the 25W Official Samsung charger. There are a few 3rd party maufacturers that make PPS chargers, but I haven't used any of them. I just went ahead and bought the Samsung one, as there was a good discount on it.

Any other charger you use will only work as a slow charger, or a fast charger (15W max) at best if it supports Qualcomm Quick Charge (QC3) standard. For 25W Super-fast charging (it's anything but super-fast, but that's what Samsung insists on calling it) you need a PPS charger, and I would recommend going with the original 25W Samsung charger.
I'll go with the Samsung 25W charger then. Thanks by the way😇👍
 
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Beefheart

Senior Member
Dec 5, 2007
5,043
1,755
England
Samsung Galaxy S23 Ultra
You can be unfortunate with any SOC in terms of die quality. Some people are simply SOL and end up with crap silicon which results in bad thermals and, if you're rooted, a restricted ability in overclocking or undervolting.

What people can't do is have a crap experience with the thermals on their S21 Ultra (or any other device) and talk as if it applies to every other device of the same model, as in post #3. It doesn't work that way.
 

tim84us

Senior Member
Mar 12, 2013
530
208
one thing i did yesterday (btw may update did not fix the heating issue) was to disable the 5g - keeping in mind i live in an area where there is excellent 5g coverage)
as soon as i turned 5g off - the heating was gone, the battery life increased and the phone felt smoother

now this was also an issue last year on s20 - seems this year is the same
something about the 5g that makes the phone get really hot
try it and see if that works
 

maharoof

Senior Member
Sep 5, 2013
60
10
28
Samsung Galaxy S21 Ultra
one thing i did yesterday (btw may update did not fix the heating issue) was to disable the 5g - keeping in mind i live in an area where there is excellent 5g coverage)
as soon as i turned 5g off - the heating was gone, the battery life increased and the phone felt smoother

now this was also an issue last year on s20 - seems this year is the same
something about the 5g that makes the phone get really hot
try it and see if that works
Heating problem while charging is fixed after I started using the original Samsung charger. But I'm still experiencing problems with video calls😕 A 20 minute video call (through Microsoft Kaizala) increases the temperature to 45°C😒 I'm not sure what's the problem. I have turned off 5G as well.
 

maharoof

Senior Member
Sep 5, 2013
60
10
28
Samsung Galaxy S21 Ultra
I haven't used the Mi charger. Tried with an old warp charger from OnePlus just for kicks and it doesnt super-fast charge the S21U. But that's becasue the propreitary fast charging standards used by different manufacturers are often incompatible.

After some research, I've found that the S21 ultra will not draw any more than 25 Watts of power (even if you use the Samsung original 45W charger). And even that 25W will work with only with a PPS (Programmable Power Supply) charger (USB C to C PPS) - like the 25W Official Samsung charger. There are a few 3rd party maufacturers that make PPS chargers, but I haven't used any of them. I just went ahead and bought the Samsung one, as there was a good discount on it.

Any other charger you use will only work as a slow charger, or a fast charger (15W max) at best if it supports Qualcomm Quick Charge (QC3) standard. For 25W Super-fast charging (it's anything but super-fast, but that's what Samsung insists on calling it) you need a PPS charger, and I would recommend going with the original 25W Samsung charger.
As I'm still experiencing problems with temperature going up in video calls, is there anyway to log the cpu usage and thermals? Maybe that would help in finding out the culprit. The battery life is not that great either. I can't figure out how much SOT I'm getting since the battery page still shows "Learning usage patterns".
 

tim84us

Senior Member
Mar 12, 2013
530
208
i think the heat during video calls is another issue - that is triggered by the actual video processing - i think you will notice if you turn the camera on for shooting a video (not live video calls) you will notice instant heating - i think that is also what is causing this - both frontal and rear cameras have huge sensors and the phone must do a lot of work to compress the live videos + data connection/wifi used during the video
i dont know the culprit but is defo related to the same issue why when taking loads of photo or long vids the phone get super hot

i mean i turn off my video during a call and the heating goes down pretty fast

all in all - it seems the same issues that plagues s20 exynos are still present in the s21 exynos - so not sure what improvements they made cz honestly is as bad as last year!!!
 
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Berserker900

Senior Member
May 7, 2020
152
57
Hey guys, i live in Kuwait and now temps are reaching 45-50°.

I don't expect the device to cool itself and i try as much to avoid using it outdoors or in my car (i have a ****ty AC)

Otherwise while at home and gaming it never exceed 40° ever.

If you dig deep into when you are using and where you will notice.

5g also drain and push temps up waaay to much.

Volte is also a factor.

Btw these are in all phones not only the s21u.

Don't be fooled guys and don't hate the ohone, it's a phone with soo many things and features running simultaneously, it has no fans and no cooling except for the paste lol.

That's my way of looking at it, i might be wrong.

Btw my sister's iPhone 12promax does the same and reach hot temps when used out and camera together.
 
As I'm still experiencing problems with temperature going up in video calls, is there anyway to log the cpu usage and thermals? Maybe that would help in finding out the culprit. The battery life is not that great either. I can't figure out how much SOT I'm getting since the battery page still shows "Learning usage patterns".
That learning usage patterns will take a few days before it starts showing data.

For thermal logging and control you can use the Samsung Labs module called Thermal Guardian. If labs app is not available in your country, download finelock from play store and get it from there. Search for appx video on thermal Guardian on YouTube for installation details
 
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varcor

Senior Member
Jul 15, 2017
907
345
San Diego
Samsung Galaxy S10+
There is a direct relationship between the amount of power used by a processor and its clock frequency. The higher the performance, the higher the power consumption and heat generated.

Samsung is teaming up with AMD on an improved SoC which is reported to make it's debut on the S22. Hopefully this will eliminate the ongoing defencies with the Exynos SoC.


Not only have some of Samsung's major stock holders pressured Samsung to resolve the Exynos debacle, there's even an online petition with over 50,000 signatures requesting Samsung stop using the Exynos Chipsets in it's flagship devices.


The only other Non-Samsung Smartphone which uses the Exynos Chip is Vivo. All others besides Huawei and a couple of Chinese Brands use Snapdragon which is pretty good indicator for the lack of confidence in Exynos SoC's
 

ione2380

Senior Member
Oct 13, 2009
438
200
Brasov
I have no heating issues with my Exynos. Sd 888 has very bad heating issues in all the phones that use it. Stop with the "inferior Exynos" bs already.
 
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  • 4
    This thread includes user's who are complaining about the Exynos 9100. No doubt it has improved compared to the 990. But user's of the 990's days aren't over, they're still dealing with an inferior chipset. Further I haven't read of one Snapdragon user or potential buyer who wants to replace or consider the purchase a Exynos variant. But there are lots of users in the Exynos Global footprint going out of their way to aquire the Snapdragon variant. It's an inferior chip by any measure and Samsung at the very least should rebrand their chipsets. They used to be the desired SoC up until three years back, now this is no longer the case, they've damaged Samsung's reputation.
    You are from US, so clearly you have the Snapdragon version, yet you rant about something you don't have and you never used. 🙂

    It's not inferior, in fact, it has the same cores as sd888, which is made by Samsung using the same manufacturing process. Sd888 has bad heating issues. See oneplus 9 Pro or Xiaomi mi11.

    You know nobody that wants to buy an Exynos? How is that relevant? How many people do you know around the world?🙂 I know plenty in my country who bought the Exynos and are happy with it. Very good reviews in local online stores are proof of that. In fact, the vast majority who buy an 21, is buying the Exynos, because that's the global version. How many do you see complaining? Some guys on xda? Those who have problems with something, are always the loudest.

    I also know plenty of guys (from a local forum in my country) who imported the sd888 version and now they regret it, because they have no warranty on it and compared the two versions and found no differences in performance.
    2
    I understand that. I would be completely fine with it if it was overheating outside with full brightness on but... it reaches around 40-41°C very easily when in use at home, with the brightness level being quite low. :(
    I'm using Microsoft Edge browser, stable version. Maybe that is the issue? Just did a quick google search and some people experience heating problems with that particular browser. Others do not.. I'll try switching to another browser and see if that solves it.




    Thanks for the reply and your insight. Yes, my device gets uncomfortable to hold in my hand more often than not (when used naked, without a case).
    Like I said above, I looked at some stats in battery tracker and thermal guardian, and the main culprit of high CPU usage and battery drain is always Microsoft Edge. Constantly over 20% of CPU usage.


    After doing further research it appears that Edge beta is much less of a battery sucker than the stable version. Fingers crossed I guess.
    I use Samsung browser and have no heating issues with it + I think it's the best android browser. I use it on all my phones.
    2
    I understand that. I would be completely fine with it if it was overheating outside with full brightness on but... it reaches around 40-41°C very easily when in use at home, with the brightness level being quite low. :(
    I'm using Microsoft Edge browser, stable version. Maybe that is the issue? Just did a quick google search and some people experience heating problems with that particular browser. Others do not.. I'll try switching to another browser and see if that solves it.




    Thanks for the reply and your insight. Yes, my device gets uncomfortable to hold in my hand more often than not (when used naked, without a case).
    Like I said above, I looked at some stats in battery tracker and thermal guardian, and the main culprit of high CPU usage and battery drain is always Microsoft Edge. Constantly over 20% of CPU usage.


    After doing further research it appears that Edge beta is much less of a battery sucker than the stable version. Fingers crossed I guess.
    Same experience as @ione2380 above. On both my S21U and Tab S7, I've found Samsung browser to be the best Android browser so far. I've tried to go back to chrome and brave, but keep coming back to the Samsung browser. None of the browsers currently do night mode as well as Samsung does.
    2
    Bruh. I returned my Mi 11 Ultra (Snapdragon 888) precisely because of the heating issue. Now I have a S21 Ultra (Exynos) and it also gets rather warm... When doing light tasks such as internet browsing. Which is something I don't get. WTF is up with phones released this year? Most seem to have heating problems.
    My Mate 20 Pro which I had a couple years ago never seemed to get as warm as the damn Xiaomi Mi 11 Ultra or S21 Ultra.

    Looks like I won't be keeping the S21 Ultra for long. Don't get me wrong, I really like this phone, but I'm extremely annoyed when it burns my hand while doing extremely basic tasks. Smh
    That is normal only if you are using your phone with data on, outside in the sun with full brightness. Otherwise you have a problem. My phone is cool all the time, unless I use it outside when it's sunny, or using video camera for more than 10 minutes. Still, it doesn't go past 45°C.
    1
    unfortunately thats just the way it is :(
    am having the EXACT same issues and i had the phone since Feb so - not something that will go away unless Samsung fixes it