Thermal design guide

Hi,
Is there a Jetson thermal design guide for K1, as it is for the X1?
Or does anyone know how the SW and HW thermal throttling is working?

//Urban

Hi Wadelius,

You can refer to this page http://elinux.org/Jetson/Thermal

Thanks for response,
but I need more detail how the throttling is working in high temperature.
We are running the board in an embedded system and the Tegra TK1 becomes
so hot that it starts to reduce the clock speed.

I’m trying to lock the chip in highest performance mode by entering these commands as root user.
echo 0 > /sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/enable
echo 1 > /sys/devices/system/cpu/cpu0/online
echo 1 > /sys/devices/system/cpu/cpu1/online
echo 1 > /sys/devices/system/cpu/cpu2/online
echo 1 > /sys/devices/system/cpu/cpu3/online
echo “userspace” > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo 2320500 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

And I can verify that all cores is running, and the clock’s is running steady.
But when I raise the ambient temperature, and read the freq with this command

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq

It report clock speed that vari and are below 2320500, but never report full speed.
The hotter it gets the lower the clock speed.

The chip gets hot, about 93 degree Celsius, but not that hot to shutdown at 105 degree.

Am I missing something when setting highest performance?
Is there any temperature regulation, limiting the performance?
If so can I control it in anyway?
Or read about how it works?

I need to be able to run the chip in extreme hot environment.
I use a decent cooling with 2 effective fans, and the board is mounted
on a big plate with good thermal connection to the GPU and other circuits on the board.

best regards
Urban

If the environment is hot, I can’t imagine that the fans are doing much good. Kinda sounds like you need a liquid cooled or refrigerated solution.

I’m stuck with the cooling solution, I can’t get any of the fancy stuff you mentioned. But ambient temperature is about 50-70 degree Celsius, so the fans are working.

That’s why I need to know more about how the thermal management works in the Tegra TK1.
So I can optimize performance with respect to our application and environment.
//Urban

Thermal throttling is used to protect chip out of heat damage, it contains HW and SW logic and controller. If ambient temperature is too high or thermal solution is not good enough, the throttling will be triggered in heavy workload then. Locking frequency in high temperature is not suggested and not supported, finding a better thermal solution is the best way for it.

Ok,
Is there any difference in behaviour between the C- and I- variants of the chip in high temperature?

You mean chip temperature and current?
Thermal sensors in chip keep reading the temperature value so as to control output performance correspondingly, that’s the relationship between C- and I- (power).

I meant that the I- model is screened, and might run a bit more efficient.
Eg You can get a bit more performance compared to the C- at the same temperature?

when you are running the TK1 at the extreme near high shutdown

OK, you meant commercial and industrial chip, right? Almost same on performance at the same temperature. The main difference is on lifetime and operating temperature range.

OK
Is there any way to reduce or shutdown things not used in the TK1,
like Audio/Video processor or Video decoder engine?

Otherwise it seems that I need to reduce power dissipation externally.

Those parts have little power needed when not working. Try to optimize thermal design please.

ok,
thanks