How Hot Is Too Warm?

[Noted Nine]

The Note 9 is obviously an excellent device, but for the money you pay, one might expect it's powerhouse innards should need no encouragement handling most of what is thrown at it.
I'm by no means a heavy gamer or use my phone for complex stuff like presentations, or editing shenanigans and the like.
A bit of Social media gazing, a lot of Whatsapp calling and video and some multitasking while I'm at it, and I'm good. I admittedly spend a lot of time on my phone (I know, need to get a life, or borrow someone else's for an afternoon or two), rather than throwing heavy-duty needs at my device.
State all this as I'm now curious to find my phone warms up quite a bit under 'duress'.
Installed a couple CPU monitoring apps when I noticed, and boom...77% CPU usage? 37 Celsius temp readings?! This while perhaps on Facebook Messenger (since deleted, always hated the app and it's innate ability to heat up every phone I've owned ever), or checking out Instagram, or being on a Whatsapp video call then minimising into PiP then checking out a post on Instagram for example.
What would happen if the Note had to handle massive multimedia tasks, throw up or meltdown?!!
Something doesn't quite add up.
It can purr along at under 30% CPU usage on the odd occasion when it isn't flustered, but that's rare, and still hardly ever don't experience the toasty feeling of ones hands becoming increasingly warm with each passing moment. Not pleasant.
Could someone please explain, give some context or help get this in check. The phone is 'hot' with raw power, and potentially the best I've used. Not loving the toaster feeling though.

 

[Mike Dee]

You may have extra stuff running in the background

 

[Noted Nine]

You may have extra stuff running in the background

Sorry for sounding daft, but how do I check? Or do I just delete apps I've put on since I got the device, and then see where it lands?
Seriously considering a factory reset, but might be drastic. Setting up this thing the way I want it was a job in itself.

 

[Mike Dee]

Sorry for sounding daft, but how do I check? Or do I just delete apps I've put on since I got the device, and then see where it lands?
Seriously considering a factory reset, but might be drastic. Setting up this thing the way I want it was a job in itself.

Settings, Device Care, Battery

 

[chanchan05]

37C temp is fine. Honestly, even for an idling device. Although of course that's dependent as well in your ambient temp. You can't very well expect it to be below ambient temp. For example it's summer where I am and ambient temp is reaching 39. I very well can't expect my CPU to be lower than 39. What kind of temps were you expecting?

 

[chanchan05]

37C temp is fine. Honestly, even for an idling device. Although of course that's dependent as well in your ambient temp. You can't very well expect it to be below ambient temp. For example it's summer where I am and ambient temp is reaching 39. I very well can't expect my CPU to be lower than 39. What kind of temps were you expecting?

 

[Noted Nine]

37C temp is fine. Honestly, even for an idling device. Although of course that's dependent as well in your ambient temp. You can't very well expect it to be below ambient temp. For example it's summer where I am and ambient temp is reaching 39. I very well can't expect my CPU to be lower than 39. What kind of temps were you expecting?

You make a good point about ambient temperature. Guess I like the temperature when the phone isn't trying to remind me it's in my hand and 'working at it'. Temperatures of no more than 33 would have been preferable, pretty much in line with ambient temp as I'm in the tropics here. But with air-conditioning on, my pet peeve is when a phone starts warming up as you start using it. The noticeable effect once you call on the CPU resources for even the most basic things can be unsettling. It however thankfully never gets hot and cools down from a warm state as quickly as it got there, especially as I've done a clear out of the cache partition, and ditched a good number of apps. Generally runs cooler even if it still spikes from time to time.

 

[mustang7757]

You make a good point about ambient temperature. Guess I like the temperature when the phone isn't trying to remind me it's in my hand and 'working at it'. Temperatures of no more than 33 would have been preferable, pretty much in line with ambient temp as I'm in the tropics here. But with air-conditioning on, my pet peeve is when a phone starts warming up when you start using it. The noticeable effect as you call on the CPU resources for even the most basic things can be unsettling. It however thankfully never gets hot and cools down from a warm state as quickly as it got there, especially as I've done a clear out of the cache partition, and ditched a good number of apps. Generally runs cooler even if it still spikes from time to time.

If you do lot of video chat like WhatsApp , the phone can warm up a bit especially long video calls.

 

[Noted Nine]

If you do lot of video chat like WhatsApp , the phone can warm up a bit especially long video calls.

Yes. I noticed.

 

[mustang7757]

Yes. I noticed.

Yeah its considered normal.

 

[chanchan05]

You make a good point about ambient temperature. Guess I like the temperature when the phone isn't trying to remind me it's in my hand and 'working at it'. Temperatures of no more than 33 would have been preferable, pretty much in line with ambient temp as I'm in the tropics here. But with air-conditioning on, my pet peeve is when a phone starts warming up when you start using it. The noticeable effect as you call on the CPU resources for even the most basic things can be unsettling. It however thankfully never gets hot and cools down from a warm state as quickly as it got there, especially as I've done a clear out of the cache partition, and ditched a good number of apps. Generally runs cooler even if it still spikes from time to time.

It gets warm because it's clocked higher than some CPUs. Heck my i5 laptop clocks at 1.7Ghz and these Notes/S lines clock at 2.6Ghz. Even if the number of cycles it churns out pretty much means it's going to warm up.

The phone also self throttles when it reaches dangerous temps. IIRC it auto shuts down at 70C.

Are you using an Exynos or Snapdragon version? The Exynos usually runs hotter. You can always turn on medium power saving.

 

[Noted Nine]

It gets warm because it's clocked higher than some CPUs. Heck my i5 laptop clocks at 1.7Ghz and these Notes/S lines clock at 2.6Ghz. Even if the number of cycles it churns out pretty much means it's going to warm up.

The phone also self throttles when it reaches dangerous temps. IIRC it auto shuts down at 70C.

Are you using an Exynos or Snapdragon version? The Exynos usually runs hotter. You can always turn on medium power saving.

Thanks for the info.
Using Exynos, thus corroborating what you've stated.
Will certainly give the medium power saving a go.

 

[chanchan05]

Thanks for the info.
Using Exynos, thus corroborating what you've stated.
Will certainly give the medium power saving a go.

Yeah. Anandtech did tests. Basically, the CPU on the Exynos S9/Note9 is faster than the one on the Snapdragon, which has a better GPU. So fast that even when capped to 70% CPU using Medium Power Saver, the thing is still faster than the CPU on the Note 8. However, they also noticed that as the speed ramped up, so did power consumption and consequentially, heat. If you don't need the extra power (which I doubt anyone who doesn't play PUBG, FortNite or Mobile Legends or other AAA Android games on their devices actually does), you're better off going Med Power Saver with regards to heat and battery consumption.

 

[Golfdriver97]

I can't remember if mobile chips throttle at the same temps as desktop chips. Let's assume for a moment that they do. The thermal threshold for desktop is 100C. Often, they start throttling at about 90-95C. Long before that, your fingers would tell you that something is up, even though glass is an insulator, you will feel the heat through the back of the phone.

In regard to heat, I wouldn't worry about it that much. Does the phone seem to bog down when you reach the temps you described?

 

[chanchan05]

I can't remember if mobile chips throttle at the same temps as desktop chips. Let's assume for a moment that they do. The thermal threshold for desktop is 100C. Often, they start throttling at about 90-95C. Long before that, your fingers would tell you that something is up, even though glass is an insulator, you will feel the heat through the back of the phone.

In regard to heat, I wouldn't worry about it that much. Does the phone seem to bog down when you reach the temps you described?

Somebody tested the Snap845 IIRC. It throttles at 68C. I'll try to find the link.

 

[Golfdriver97]

Somebody tested the Snap845 IIRC. It throttles at 68C. I'll try to find the link.

68-70 wouldn't surprise me either. Since the heat dissipation is passive, a lower throttle temp is reasonable.

 

[chanchan05]

Here's a link for SoCs from 2014 tested for temps. You'll notice that the general majority has average temps north of 33, and the Exynos 4412 has an average running temp of 36C
https://www.xda-developers.com/processor-temperature-results-for-tens-of-socs-how-hot-is-your-chip/

Here's a guy who tested the Snapdragon 845 on OnePlus6 and it reached 70C
https://linustechtips.com/main/topic/970209-mobile-procesor-temperature/

 

[adegbenroagoro]

37C temp is fine. Honestly, even for an idling device. Although of course that's dependent as well in your ambient temp. You can't very well expect it to be below ambient temp. For example it's summer where I am and ambient temp is reaching 39. I very well can't expect my CPU to be lower than 39. What kind of temps were you expecting?

Exactly.

 

[Hermes Hidayat]

Well, my Note 9 with Exynos with High Performance Mode on just went 43 degrees...