Corrupted images on Vukan backend #439
Description
I'm getting either corrupted or inconsistent images on Vulkan backend, for any resolution other than 512x512.
My system is a Linux PC with a Ryzen 3400G, almost-vanilla Debian 12 (using the distro graphic stack). All following tests with:
--type f16 --lora-model-dir ./LoRA --model ./SD/dreamshaper_8.safetensors --prompt 'a fantasy character, detailed background, colorful<lora:lcm-lora-sdv1-5:1>' --cfg-scale 1.0 --sampling-method lcm --steps 4 --rng cuda --seed 42 -b 1 --color
, and a script alternating resolution and compiled binary (Vulkan or CPU backend).
320x512:
| Vulkan 1 | Vulkan 2 | CPU |
|---|---|---|
 |
 |
 |
Vulkan images look ok-ish (for such a small resolution anyway), but the same seed should produce the same image. And the CPU render looks quite different.
Second test, 384x384; similar behavior (changes between Vulkan 1 and 2 may not be apparent on the thumbnail):
| Vulkan 1 | Vulkan 2 | CPU |
|---|---|---|
 |
 |
 |
The third test, 448x448, gets weird:
| Vulkan 1 | Vulkan 2 | CPU |
|---|---|---|
 |
 |
 |
At first, I blamed my PC drivers. But then, the 512x512 test:
| Vulkan 1 | Vulkan 2 | CPU |
|---|---|---|
 |
 |
 |
Looks absolutely fine, and identical between Vulkan and CPU.
In summary:
- 512x512 works fine;
- any other resolution produces inconsistent images between runs;
- some resolutions introduce artifacts
(related: #122 )