BROKEN OUTPUTS — Qwen-Image-2.1 (2×GPU balanced)

Status: BROKEN / DO NOT USE

2026-09-21: the broken PNGs and .broken marker files listed below were deleted at the user’s request; only this record remains.

Source project used to generate these

• Model: Qwen/Qwen-Image-2.1 (Qwen-Image-2.1)
• Pipeline: diffusers.QwenImage21Pipeline
• Script: WORKSPACE/temporary-artifact
• Config: torch_dtype=bfloat16, device_map="balanced" across 2× RTX 3090
• Run: CUDA_VISIBLE_DEVICES=1,2 conda run -n qwen-image-21 python WORKSPACE/temporary-artifact
• Steps/size: 40 steps, 1024×1024, seeds from random.Random(2026)

Failure

Every image is flat gray noise (no content). The device_map="balanced" sharding of the diffusers pipeline is the suspect: latents/tensors split across devices, so the denoise loop never produces a coherent image. Speed was fine (48.1 s, 1.42× vs 68.3 s single-GPU baseline) but output is invalid — the 2-GPU path is not usable as-is.

Files

file	md5 (short)	verdict
qwen21_2gpu_1.png	53cbc3167ff5	BROKEN (flat gray noise)
qwen21_2gpu_2.png	e4072fe100ea	BROKEN (flat gray noise)
qwen21_2gpu_3.png	b5ce06d363dd	BROKEN (flat gray noise)
qwen21_2gpu_4.png	7fe1bed571c0	BROKEN (flat gray noise)
qwen21_2gpu_5.png	1214027f06ea	BROKEN (flat gray noise)

Working alternatives (same model): single-GPU bf16 + enable_model_cpu_offload() (WORKSPACE/temporary-artifact) and fp8 weight-only DiT + offload (WORKSPACE/temporary-artifact).