Jetson Tk1 Temperature

Autonomous Machines Jetson & Embedded Systems Jetson TK1
1

Could someone please explain the different thermal zones ?

root@tegra-ubuntu:~# cat /sys/devices/virtual/thermal/thermal_zone*/temp
37000
36000
36500
36500
32000
32750

Display your K1 temperature with a small perl App:

install perl/tk before:
sudo apt-get install perl-tk

Save the script to your home folder and make it executable.
#!/usr/bin/perl -w
#peba@inode.at

use Tk;
$main=MainWindow->new;
$main->resizable (0,0);
$temp=“–”;

$myframe=$main->Frame ();
$myframe->Label (-text => ‘Temperature:’)->pack ();
$temp_label=$myframe->Label (-text => “$temp”)->pack ();
$myframe->pack();

$main->repeat(1000,&update_temp_label);
MainLoop;

sub update_temp_label {
$temp=cat /sys/devices/virtual/thermal/thermal_zone0/temp;
$temp_label->configure(‘-text’ => $temp);
}

2

If you run “cat /sys/devices/virtual/thermal/thermal_zone*/type” you’ll see that each of those thermal zones has a different name. The ones with “-therm” in their name are for sensors internal to the TK1 chip. “Tdiode_tegra” measures the temperature at the edge of TK1. “Tboard_tegra” measures the temperature of the circuit board (though I’m not sure of the exact location).

3

Thanks guys, I’ve created the Wiki page [url]http://elinux.org/Jetson/Thermal[/url] with this info.

4

What are the temperature limits?

Thanks.

5

You souldnt worry too much if its below 80c but I would rather keep it a 70 range at most.

6

Using the same passive Heatsink as on the wiki I get around 55 degrees celsius after running the CUDA smoke-particles demo for a while (about 23 deg room temperatur).
The sink feels warm then but still not hot.
At 26 deg ambient temperature the idle-Temperature is now:

CPU-therm-virtual-0
Adapter: Virtual device
temp1:        +44.0°C  (crit = +101.0°C)

GPU-therm-virtual-0
Adapter: Virtual device
temp1:        +45.0°C  (crit = +101.0°C)

MEM-therm-virtual-0
Adapter: Virtual device
temp1:        +43.0°C  (crit = +101.0°C)

PLL-therm-virtual-0
Adapter: Virtual device
temp1:        +43.5°C  

Tboard_tegra-virtual-0
Adapter: Virtual device
temp1:        +37.0°C  

Tdiode_tegra-virtual-0
Adapter: Virtual device
temp1:        +40.5°C

(output from sensors [sensors version 3.3.4 with libsensors version 3.3.4])

7

Temperature limits would be different for different parts of the board or chip, such as whether it is measuring the temperature within the SOC (where higher temperatures can be tolerated). If you search the web for typical temperature limits of modern SOCs & chips you will see that the cutoff limits inside the chip are much higher than what you are talking about. (I’m not sure if the “crit = +101” showing a critical limit of 101 degrees Celcius is the actual limit being used or not but it does give that impression).

8

We also installed a passive heat sink, lm-sensors, then ran the CUDA smoke-particles demo, and observed the following readings:

ROOM TEMP: 22.8 deg

ubuntu@tegra-ubuntu:~$ sensors
CPU-therm-virtual-0
Adapter: Virtual device
temp1:        +63.5°C  (crit = +101.0°C)

GPU-therm-virtual-0
Adapter: Virtual device
temp1:        +65.0°C  (crit = +101.0°C)

MEM-therm-virtual-0
Adapter: Virtual device
temp1:        +61.5°C  (crit = +101.0°C)

PLL-therm-virtual-0
Adapter: Virtual device
temp1:        +60.5°C  

Tboard_tegra-virtual-0
Adapter: Virtual device
temp1:        +46.0°C  

Tdiode_tegra-virtual-0
Adapter: Virtual device
temp1:        +59.2°C
9

enthuse, my TK1 is running much hotter than yours and it seems like we have similar setups. What heatsink did you use? This is my setup:

3800×2533 1.68 MB

I installed an Enzotech CNB-R1 Forged C110 Pure Copper Heatsink http://www.newegg.com/Product/Product.aspx?Item=N82E16835708002 with thermal compound and while running the Smoke Particle demo for several minutes I get the following readings. Ambient room temperature @ 25 deg.

ubuntu@tegra-ubuntu:~$ sensors
CPU-therm-virtual-0
Adapter: Virtual device
temp1:        +71.0°C  (crit = +101.0°C)

GPU-therm-virtual-0
Adapter: Virtual device
temp1:        +73.5°C  (crit = +101.0°C)

MEM-therm-virtual-0
Adapter: Virtual device
temp1:        +64.0°C  (crit = +101.0°C)

PLL-therm-virtual-0
Adapter: Virtual device
temp1:        +67.0°C  

Tboard_tegra-virtual-0
Adapter: Virtual device
temp1:        +45.0°C  

Tdiode_tegra-virtual-0
Adapter: Virtual device
temp1:        +67.2°C
10

@BrandonEpicAero I think your temperatures arent bad at all. The heatsink you use is quite small actually and a bit funny (to me) on jetson.

11

Hi,
I used the same heatsink as in the Wiki. That “huge” tower-like beast.
To me it seems like i.e. the “HEAT” example from the “CUDA by example” book sets the GPU much more under stress than the smoke particles…
I can provide more data and pictures.
The values I posted were taken with an OPEN case, i.e. the whole heatsink exposed to air.
Yours looks much smaller (and nicer) but might turn out to be insufficient for reliable long-term intense use?
Cheers,
Martin

12

We decided to use the smaller heatsink due the the chest pack case we are developing for it and completely forgot it wasn’t the same as the wiki. lol We are using the TK1 for a mobile cognitive neuroscience research project involving skydivers. Luckily our heavy load scenario will occur only in free-fall and will have sufficient airflow. Thank you for your response!

-Brandon

13

@BrandonEpicAero Wow thats very cool what you are doing with it :O

14

Is there a way to read the temperature sensors from c++ code?

15

You can read the sensors through sysfs using c or c++:

[url]https://www.kernel.org/doc/Documentation/hwmon/sysfs-interface[/url]

16

Hello I would like to know where the sensors are located exactly?

The first four sensors are inside the SOC that is clear but where on the Jetson is the TMP451 Sensor that accounts for tboard and tdiode. From what I read in the datasheets this is a combined sensor for both values. It is referenced as the external thermal sensor and referring to the Platform Design Guide ( [url]http://developer.download.nvidia.com/embedded/jetson/TK1/docs/3_HWDesignDev/TegraK1_Embedded_DG_v03.pdf[/url] , Page 84) it should be located 15-20 mm from Tegra and between PMIC and CPU. This is also the only section in any of the manuals and specifications with information on that sensor.

Does anyone know where it is located or where I can find more info about it?

Best regards
Gerald

17

The thermal sensor chip is U2C2,it on the TOP side,under the edge of SOC Fan and close to the SATA connector[J2D1]

18

Jetson TK1 board, what is the maximum allowable temperature of each component (CPU, Diode, GPU, MEM, PLL, ADE, VDE) as per manufacturer specification?

19

Any reference document on above reading?