Jetson Thor reboots under AI workloads and when connecting 2.5" HDD

Hi everyone,

I’m facing serious stability issues with my brand new Jetson Thor and I’m trying to understand whether this is a hardware, power, or software problem.

The system reboots instantly (no alerts, no warnings, no logs) under specific conditions and sometimes even randomly.

  • When I run models on Ollama:

    • large models (e.g. gpt-oss:120b) reboot the board almost immediately

    • smaller models (e.g. qwen3:4b) allow 1–2 responses, then the system reboots

  • When I generate images with ComfyUI (e.g. Flux or similar models), the system reboots as soon as generation starts

  • Every time I connect a 2.5" magnetic HDD via USB, the system reboots immediately; after reboot, the drive is accessible and works normally

  • The board can also reboot randomly even when I’m not doing anything heavy

I also ran some tests that did NOT cause reboots:

  • CPU stress (stress-ng) → stable

  • Light CUDA test (small torch tensor on GPU) → stable

Crashes seem to be triggered by sustained GPU + memory load or by USB power draw (e.g. HDD spin-up), but they can also occur randomly, although less frequently.

Could this indicate power delivery instability (even with the original PSU)? Or could it still be software-related? Does the fact that the board reboots instantly clearly point to a hardware/power issue?

Any help to understand or isolate the problem, and suggestions on how to fix it, would be greatly appreciated.

Thanks!