Many of you might have this question in your mind.How the performance is different for two smartphones having the same processor and chipset and similar other configurations?. Difference in customized android skins is a fair argument, since there are significant difference in performance between a device which is loaded with MIUI (Older versions) and stock android device which are close in specifications. This post discusses about processor heating and throttling in smartphones.
This points out that there is more than just difference in Android UI that affects a smartphone or laptops performance and battery life. One major issue is the cpu throttling.
What is processor heating and throttling
This is applicable to smartphone processors as well as desktop processors such as Intel/AMD processors. Every processor heats up when you use it. One classic example is to think the processor as the engine of a car. If you drive the car at a speed of 40 mph, the car runs really smooth and well. The story changes when you ride at your car’s max speed, say at 150 mph. As you rev up to that speed for a long time, the car engine will heat up and the performance will reduce gradually.
The same thing is applicable even to processors. Lets take an example of Snapdragon 821 chipset. It is available at two variants – One is clocked at 21. GHz and the other one is clocked at 2.35 GHz. The popular OnePlus 3T is using the 2.35 GHz variant while the Google Pixel uses the 2.1 GHz variant. You might ask why?.
If you see the gaming reviews of One Plus 3T heats up quite high with extended gaming (Like you over speed a car engine) but the pixel was managed to stay cool during hardcore gaming. There are some trade off too. The Pixel is using a low powered processor than One Plus 3T which helps in getting a better battery life where as the 3T will perform slightly better with draining slightly more battery life.
So it is up to the manufacturers to select at what clock frequencies they want their devices to be run. part from that, they can tweak the characteristics of the processor with the kernel they are using on their smartphones.
Will the processor melt if I use the heating smartphone for long time ?
No. All modern processors (Both smartphone and desktop processors) have thermal limits. If the processor overheats above a set level, it will shut down itself.
What is the maximum temperature which doesn’t cause issues while using a smartphone?
The surface temperature for a smartphone can be measured using a heat gun. If your smartphone’s surface (It is the temperature that your feel on the back of your device, actual processor will have a lot higher temperature) will get uncomfortable to touch when it touches anything above 44 degree Celsius.
What is throttling down ?
Suppose the processor is running at high clock frequencies for a long time, it will normally heats up. Once the cpu senses the temperature above a threshold level, instead of running in the max clock speed, say 2.1 GHz it will reduce the clock speed to 1.4 GHz. This is done automatically inside the processor and end users cant override unless they tweak the kernel.
Lowering of clock speed due to high temperatures is the reason why some times you notice lags while you plays heavy games on under powered smartphones for long time.
Smartphones with same processor will behave differently sometimes while playing games. One such example is the the CoolPad Cool 1 Vs Samsung Galaxy C9 pro. Both devices has the SD 653 chipset, but the coolpad struggles to run games like Asphalt 8, temperature shoots up to 48 degrees where C9 pro managed to run these games very well. Here, Samsung did a better job in optimizing the processor and frequencies at which it is running.
As you know, every processor dissipates heat when it is used. But how a smartphone dissipates heat is also very important. These days, most of the smartphones are coming with metal body which really helps in thermal dissipation. There’s again a cost which you have to pay. Earlier smartphones had a plastic/poly carbonate back, they never used to heat up a lot except the areas close to the camera. But with recent metal phones, the entire back gets heated up with the usage. This means that the metal cover of the smartphone is acting a as a heat sink for the smartphone.
The above things are also valid for the GPU. Let’s say if your smartphone has a 1080 p display (~ 2 million pixels) and another brand has the smartphone with same processor and GPU with a quad HD screen – There will be more load on the GPU on the later one since the phone with quad HD screen has to work twice harder than the other phone to push those double amount of pixels.