[HTC 10 Guides, News, & Discussion] Haldi4803:
Heat dissipation or Longterm throttling

Because XDA did the Heattest on the Pixel XL i realized i've never done a full length throttling test on my HTC 10.

Surely i know PnPmanager throttles down CPU to 1.6ghz and 1.32ghz afterwards but how hot does the phone actually get?

Sadly i still cant find my infrared thermometer..... so i've taken Battery Temperature instead. While the CPU temperature is way above that the Batterytemperature is closer to the surface/overal temperature of the device.

The phone was put in Flight Mode, WiFi off, Minimum Screen brightness, 1.98.709.5 Rom with ElementalX Kernel v23 and Task Migration set to 100% (Originally both Big cores drop to 60% if temperature gets too high.)

Running StabilityTest app to load all cores, using Trepn Profiler for CPU Frequency, Battery Level and Power drain with BatteryLog app for BatteryTemperature everytime the Batterylevel changes. The phone was placed without any cover or case onto my wooden table.

The Test was not Fair as i had 20°C Roomtemperature but did NOT give the phone any time to cool down. While normally using it i started the Benchmark with a Batterytemperature of 30°C. You can see the Battery rising over time till it reached 49°C

If you're wondering why the Test only ran 100 Minutes? well i started at 84% Battery and stopped at 11% so yeah, too much Power drawn^^ 7.85Wh to be precise. (Battery is specified for 11.5Wh so that would be roughly 69%, not bad huh? Lost 74% Batterylevel)

Oh... and while we're at it... it took 98 Minutes to drop from 81% to 11% (all on 1324mhz all cores) Thats roughly 42% per Hour.... phew.

The Average Powerdraw over the whole test was 4.5W while the Median was 4.46W

So what did the Frequency do? PnPmanager is already aware that the phone simply cannot handle a greater poweroutput and limits the phone to 1324mhz pretty fast.

If you wonder about the Peaks at 96 and 103 Minutes, thats AppLaunchBoost function from pnpmgr, while i left my phone running alone for most of the time, at these two points i've taken my phone and opened Trepn profiler to check how it's been running so far. So when you switch an app or open a new one the phone will boost at max clock for 1 or 2 seconds, even though it's already pretty hot.

I wonder how well that works when you are Outside under bright sunlight with maximum Screen brightness and 35°C Temperature. ^^

So let's take a closer look at the first few minutes. Again, i did NOT start at room temperature, the phone was already warm when i started the test.

But that doesn't matter anway, as CPU Throttling is not dependant on Batterytemperature but CPU temperature.

edit:

Here we go! Freezer test :D

Freezing your phone!

As impatient as i am i've taken the phone out of the freezer every 10 Minutes, you can see that in the Temperature increase by 5°C and sudden frequency drop.

This also shows pretty well that Battery Temperature is NOT responsible for CPU throttling but CPU Temperature... makes sense? Yes, but common, ~65°C on the CPU as maximum and the phone Throttles down? my Xperia Z2 managed 90°C on the SoC before the Safety shutdown kicked in when i deactivated IntelliThermal ^^

Inside the Freezer with constant cooling the CPU kept going at 1.9ghz minimum, pretty impressive.

This time i also used C3 Battery Monitor with a 5 second interval for logging Battery infos. Using the logged Ampere and Battery Voltage i compared this versus Trepn Profiler's BatteryPower value.

But as you can see, same as Trepn Profilers 30 sec interval for BatteryPower, C3 Battery Monitor updated every 5 seconds but the value only changed every 30 seconds.

Looks like i have to write my custom shellscript for updating CPU temp into a file every second or faster.....

Taking a closer look at the "Not in the Fridge Anymore" part of the Test.

Even though the Batterytemperature is below 25°C the CPU itself is already too hot and the Big cores clock down to 1324mhz.

You can see the Batterytemperature being updated every 30 seconds.... kinda suck.

But oh well.... This time with a completly cold phone! from 13°C Case/Battery it takes about 3 Minutes until the CPU throttles from 2.15ghz to 1.32ghz, so there is no "Sustain" available at all anyway ^^