P: Photoshop Beta 27.9.0 (Mac M1 Pro): GPU rendering causes blotchy artifacts in smooth gradients
Photoshop version: 27.9.0 Beta
Computer: MacBook Pro M1 Pro
Operating System: macOS Tahoe 26.5.1a
Issue:
Smooth gradients and dark vignette backgrounds display with blotchy, cloud-like artifacts when Use Graphics Processoris enabled.
Steps to reproduce:
- Open an image with a smooth dark gradient or vignette.
- Enable Preferences → Performance → Use Graphics Processor.
- Observe blotchy artifacts in the gradient.
- Disable Use Graphics Processor.
- Reopen the image.
Result:
The artifacts disappear immediately when GPU acceleration is disabled.
Additional information:
- The same JPEG and TIFF display correctly in Lightroom Classic.
- GPU Compatibility Check reports the Apple M1 Pro as fully compatible.
- Changing OpenCL and GPU Compositing individually does not resolve the issue.
