AMDGPU performance regression in Kernel 7.0.0-28.28 - Kernel - Ubuntu Community Hub

AMDGPU performance regression in Kernel 7.0.0-28.28

Project Discussion

Kernel

kleber.souza

July 16, 2026, 7:59am

Introduction

Hello everyone,

The Ubuntu Kernel Team would like to acknowledge a performance regression identified within the amdgpu driver for the upcoming 7.0.0-28.28 kernel release. We want to thank our community testers and early adopters for identifying and reporting this behavior.

What to Expect

Affected users may experience a significant performance regression, particularly when running compute-heavy workloads that utilize ROCm, such as Stable Diffusion XL (SDXL) inference via ComfyUI. This manifests as a drastic increase in processing time—reports indicate slowdowns of up to 42× (e.g., from 9 seconds to 388 seconds). Please note that this is a throughput degradation rather than a system lockup.

Who is Affected

This is a targeted regression primarily affecting Ubuntu 26.04 users as well as users on the Hardware Enablement (HWE) stack for Ubuntu 24.04, who are currently scheduled to be migrated from the 6.17 to the 7.0 kernel. While the scope is still being refined, we have confirmed reports of this behavior on AMDGPU-based systems utilizing ROCm, specifically impacting compute-heavy workloads like Stable Diffusion XL (SDXL).

Roadmap

The Ubuntu Kernel Team is currently prioritizing the release of critical security fixes contained in the upcoming kernel release to ensure the safety of our users. While this specific regression will be present in the 7.0.0-28.28 release, we have already identified the resolution.

The fix is queued to be applied to the very next immediate batch of updates containing critical fixes. This approach allows us to balance the urgent need for security patches with the requirement for long-term performance stability.

Mitigation

In order to mitigate the performance regression, affected users are recommended to stay in their current kernel version until a kernel update is released with the proper fix.

References

For those interested in the technical background or following the upstream discussions, please refer to the following:

ROCm Issue Tracker: AMDGPU Performance Regression

ComfyUI Issue Tracker: Performance Regression on AMD Hardware

5 Likes

Ubuntu Weekly Newsletter Issue 953

yasirel

July 16, 2026, 12:50pm

What a headache kernel 7.0 is giving my AMD hardware… I hope it can be fixed very quickly. Thanks.

fireon

July 16, 2026, 4:35pm

Am I understanding this correctly, does this only apply to ROCm, not the gamers among us?

luisalvarado

July 16, 2026, 6:30pm

Appreciate the honesty, transparency and timely response about when it would be fixed. So thank you.

Very VERY different from the posts mentioned in phoronix about the issue.

2 Likes

Powered by Discourse, best viewed with JavaScript enabled