Core M tablet + x264 pausing

[kadajawi]

Hello, not sure where I can ask this cause I have no idea what the cause of the problem is.

I am trying to encode several files one a Core M tablet running Windows 10, x264 build 2705 IIRC.

But the encoder keeps pausing the encode. I haven't been able to find a pattern, if I press Strg C it continues. It is normal and should be that the tablet slows down when it runs too hot. And it does that. Depending on the temperature it will also speed up. Recently it didn't want to run for more than a couple of seconds, at that time the tablet was running on battery, but it was cooled down, so heat wasn't an issue. Battery was full. Another time I had it running on battery for hours, it was hot, but worked.

Maybe it is quick temperature changes? Once the tablet warmed up while it was cooled down it continued running.

Any suggestions are very much appreciated, this is driving me mad.

[raffriff42]

Pretty sure it's a heat issue. Monitor CPU temperatures, and take a break when temps get too high -- for me, that would be anywhere above 90-92°C. Or do CPU throttling - see this thread (http://forum.doom9.org/showthread.php?t=173670). Personally I would not dare push a machine to thermal shutdown on a regular basis.

I don't know what CPU temperature monitoring program to suggest for your tablet. You'll have to try a few. I use Afterburner (https://gaming.msi.com/features/afterburner) to put a temp readout in the system tray. Have used Speedfan (http://www.almico.com/sfdownload.php) previously, for the same purpose. (Don't use the overclocking features of either one, you're in enough trouble already!) StainlessS likes CoreTemp (http://www.alcpu.com/CoreTemp/), which seems to have the most features related to temperature monitoring. There may be others.

[kadajawi]

These machines and CPUs are designed to run into throttling... the official clock speed is 0.8 GHz, but they can go up to 2 GHz if the temps allow it. At around 90 degree the clock speeds are lowered.

What I noticed is that x264 pauses/the task is frozen when there are big temp changes... but only when I cool the machine. i.e. it will be fine ramping up and working at full speed until throttling when left by itself... and it can work like that for days without interruption. But should I then take the machine and place it on metal, so that the heat gets dissipated faster and better, the task will freeze. With some attempts I can get it running, and then it will be able to do about 300-400 MHz more continuously, i.e. run at 1700-1800 MHz all the time, with not that much passive cooling. Impressive little CPUs.

But this is a very odd behaviour, and I have no idea how to google for something this odd, or where I should ask. Sounds like something intentional, but why?

[vivan]

Does it happen on external power? Maybe it monitors power consumption and stops apps that suck battery too much (low temp -> high clocks -> high consumption).
What happens with other CPU intensive applications (7-zip benchmark, Prime95, etc)?

Still, while it's theoretically possible and makes a bit of sense (monitoring temp/power and pausing application with highest CPU usage) I've never heard about utilities that could do that.

[StainlessS]

Apparently in XP, M$ introduced some kind of OS governed throttling (was absent in W2K).
In later versions of Windows 10, they hand over control back to the CPU.
On XP, I used RMClock and SpeedSwitchXP, to take back control from the OS.

Speed Shift is the new Intel name for what was SpeedStep, maybe something of interest here:- https://www.google.com/?gfe_rd=cr&ei=tAFqVuTzKdLS8AfknKK4BQ&gws_rd=ssl,cr&fg=1#q=Core+M+tablet+windows+10+%22speed+shift+%22

[raffriff42]

This article explains thermal management in Windows. Please read and try some of the suggested diagnostics.https://msdn.microsoft.com/en-us/library/windows/hardware/mt637221(v=vs.85).aspx
Skin temperature sensors
Monitoring the skin temperature is critical in ensuring that the user is protected at all times. If the temperature on the skin is too hot to handle safely, the system should take immediate action to shut down the system...

Event logs
Windows records important thermal information in the event logs. This information can be used to quickly triage thermal conditions on any PC running Windows 8 or later without the need for additional tracing or tools. The following table contains the full list...

Performance counters
Performance counters offer a real-time information on the thermal behavior of the system. The following three pieces of data are polled for each thermal zone...

[kadajawi]

It happens on AC too.

I went through the event logs but couldn't find anything.

Skin temperature makes not so much sense, cause it mostly happens when the temps aren't so high.

The problem now also occurs when not being cooled, but mostly still with big temp changes.

I have tried running x264 without a batch file that triggers it... same issues.

Next up is a stress test with another application, we'll see how that goes.

[kadajawi]

I tried a GUI encoder... x265. Didn't freeze...

[kadajawi]

After further testing it only happens when run through command line or power shell... both with x265 and x264. Odd.

I discovered that I can resume by right clicking in the cmd or powershell window...

[LoRd_MuldeR]

Just to be sure:

You are aware that if you mark a portion of the text in a console window (e.g. via Edit -> Mark), this will "freeze" the whole console - and thus block the app that is connected to the console - until you confirm your selection by pressing Enter?

This can happen "by accident" very easily when you have the so-called "Quick Editing Mode" enabled, because then you will start marking text (and thus freezing the console) just by left-clicking into the console window...

[kadajawi]

Just to be sure:

You are aware that if you mark a portion of the text in a console window (e.g. via Edit -> Mark), this will "freeze" the whole console - and thus block the app that is connected to the console - until you confirm your selection by pressing Enter?

This can happen "by accident" very easily when you have the so-called "Quick Editing Mode" enabled, because then you will start marking text (and thus freezing the console) just by left-clicking into the console window...
It pains me to say this, but... :thanks:

That was it, it seems. Obviously I wasn't aware of this feature/didn't pay it any attention. Oh well, now it works! :)