Heat Disipation

Where is the majority of the heat in the Xavier Dev-Board created and where is the majority of it dissipated?
Why I ask, I notice that the side of the xavier gets very hot and i wonder how much of the heat is dispitated by the fins+fan vs. for the case to air contact.

Hi, please check the thermal design first: https://developer.nvidia.com/embedded/dlc/jetson-agx-xavier-series-thermal-design-guide

Yes I have already, but from my read through it seems very limited, focusing on internal heat transmission and makes alot of engineering assumptions e.g. that the fins and case are a single unit (in regards to thermal conductivity) and that heat is spread uniformly on a “balanced workload” i know few systems where that would ever be the case and simply feeling around the xavier tells me that’s not the case for atleast a “common workload” (what the agx is advertised for).

I was hoping that there would be more information about why there’s significant heat coming from the side of the unit and the difference of heat dissipation from the fins to air and case to air. This could be easily seen with a heat camera? but i dont have one of those.

The main goal of heatsink is to dissipate heat as uniform as possible. The heat dissipation is different too for different kind of workload. In general the hot points are near to Xavier chip. The fan speed is dynamic following the thermal zones value which are in different parts in Xavier chip and on board. No such data of “how much of the heat is dissipated by the fins+fan vs. for the case to air contact” as the key point of thermal control is to make chip temperature under the threshold as you can see in the guide.

Bit of a strawman answer there. I never asked about the fan speed or the thermal control performance. What I’m asking is specifically about the relative performance of the passive (case) and active (fins + fans) components, answering another question doesn’t answer mine.

Let me rephrase the context. If say I’m not happy with the current job of the dev kit in removing heat from the system, then I’d want to attach a coldplate. It would be a simple process for me to just attach it to the case itself, maybe on that hot side that I’ve identified. However since I have no information on the case’s performance as a heat sink in relative performance to the fins+fans, then it could be that the case is a poor dissipation unit and attaching the coldplate to the case doesn’t really do much. OR, it could be that it does alot and going to the effort of fixing the active cooling components in some way was unnecessary.
I can’t know unless someone has already done the test for the performance of the cooling components that are installed on the dev kit, and given that the passive and active components are acknowledged in the thermal guide I really would’ve expected NVIDIA to of done that test when they were in the engineering phase as it would’ve informed them of how large a heat sink, fan, to what grade, etc. they would’ve needed.

As said in guide, "Jetson AGX Xavier enables a wide variety of applications that may exercise different components on the module. The variation between applications will cause variation in heat loads on the different components on the Jetson AGX Xavier and hotspots in different logical partitions of the Xavier SoC. While Jetson AGX Xavier is designed to spread the heat and make the thermal performance as consistent as possible, different applications have different levels of thermal performance. "

So the relative performance difference between you said case and fin+fan is also dynamic. And so we have no such data of “how much of the heat is dissipated by the fins+fan vs. for the case to air contact”, and as you can see in guide, the key point of thermal design (including dev kit) is to make “the temperature of the TTP must always be kept within this 80 °C limit to maintain the specified performance and reliability.”