RTX 5080 EGPU Hard Lock With Thunderbolt 5

by Alex Johnson 43 views

Introduction: The Perplexing RTX 5080 and Thunderbolt 5 Conundrum

The realm of external GPUs (eGPUs) has opened exciting possibilities for boosting the graphics performance of laptops and other devices. However, the path isn't always smooth. This article dives into a particularly vexing issue: the hard lock encountered when using an NVIDIA GeForce RTX 5080 with a Thunderbolt 5 eGPU enclosure. Specifically, it focuses on scenarios where CUDA operations trigger a complete system freeze, requiring a power cycle to recover. We'll explore the problem, its potential causes, and how it mirrors similar issues observed in the past. We'll examine the technical details of the setup, including the specific hardware, software, and kernel parameters, to understand the intricacies of the problem. This guide aims to provide insights, troubleshooting steps, and possible solutions to help users facing similar challenges.

This issue has been reported by a user running Rocky Linux 10.1 on a Lenovo ThinkPad X1 Carbon Gen 11. The setup includes an RTX 5080 connected to a Sonnet Breakaway Box 850T5 Thunderbolt 5 eGPU enclosure. The problem manifests when attempting to run any CUDA operation, causing an immediate hard lock of the system. The nvidia-smi command works perfectly at idle, indicating that the GPU is recognized and initialized correctly. The issue resembles the one previously encountered with an RTX 5090 via OCuLink, which was resolved by switching docks. This article meticulously analyzes the reported issue, offering a detailed understanding of the hardware and software components involved, and the symptoms observed.

The Hardware and Software Landscape: A Deep Dive

Understanding the components is key to troubleshooting. The user’s setup includes:

  • GPU: NVIDIA GeForce RTX 5080 (GB203). This is the graphics card at the heart of the problem.
  • eGPU Enclosure: Sonnet Breakaway Box 850T5 (Thunderbolt 5). This enclosure provides the interface between the GPU and the host system via Thunderbolt 5.
  • Host: Lenovo ThinkPad X1 Carbon Gen 11. The laptop serves as the host system, connecting to the eGPU enclosure via Thunderbolt.
  • Thunderbolt Controller: Intel Raptor Lake-P Thunderbolt 4 (host), USB4/TB5 (enclosure). The Thunderbolt controller on the host laptop manages the connection to the eGPU enclosure.
  • Operating System: Rocky Linux 10.1. The operating system on the host system.
  • Kernel Release: 6.12.0-124.13.1.el10_1.x86_64 (PREEMPT_DYNAMIC).

This intricate interplay of hardware and software components creates a complex environment where compatibility issues can arise. The Thunderbolt 5 eGPU enclosure is a relatively new technology, and compatibility with specific GPUs and operating systems may not always be seamless. The choice of the operating system and the kernel version also significantly impacts the overall functionality of the eGPU setup. Additionally, the kernel parameters used, such as pcie_ports=native, pcie_aspm=off, pcie_port_pm=off, and pci=assign-busses,realloc, play a crucial role in enabling the correct functioning of the eGPU.

The Problem: Hard Lock on CUDA Operations

The core issue is a hard lock that occurs when any CUDA operation is initiated. This typically manifests when running a simple CUDA test, such as `python3 -c