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v3.4.8 - SAM3 Nodes Removed (Stock Loader Support Confirmed)

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@ussoewwin ussoewwin released this 29 Aug 21:59
· 2 commits to main since this release
EN 中文

HSWQ v3.4.8 — SAM3 Nodes Removed (Stock Loader Support Confirmed)

🗑️ Removed

  • HSWQ SAM3 Loader (ConvRot INT8) and HSWQ SAM3 Detect were removed from the repository tree.

📖 Background (why)

The SAM3 ConvRot INT8 node work was published in v3.4.7. After posting on r/StableDiffusion, a community member pointed out that these checkpoints work with the default Comfy SAM 3.1 node. Re-testing confirmed it: the stock CheckpointLoaderSimple (and the default Comfy SAM3.1 node) load ConvRot INT8 SAM3 checkpoints correctly — the dedicated loader turned out to be unnecessary.

The reason stock loaders work is the HSWQ startup patch (_patch_load_state_dict_guess_config_int8, gated by is_sam3), which automatically:

  • attaches MixedPrecisionOps (int8_tensorwise) so Linear layers stay true INT8 in VRAM (TensorWiseINT8Layout), and
  • dequantizes and remaps the CLIP keys so the text encoder loads without the "clip missing" warning.

The error seen during the earlier test was a user-side oversight, not a loader incompatibility.

🔧 What changed

  • Tree restored to the pre-SAM3 baseline d33862a (191ddbc).
  • History intentionally retained: all SAM3 work — the nodes, the patches, and the complete technical guide — remains in the git history under v3.4.7 for future reference.
  • CHANGELOG updated (EN + 中文).

📦 Related

💡 Technical notes from the experience

  • Supporting ConvRot INT8 for SAM3 took several days of development; unlike image-generation UNets, the ConvRot rotation handling for ControlNet and CLIP was the difficult part.
  • The motivation was storage savings as much as VRAM: converting CLIP and ControlNet to ConvRot INT8 freed about 40 GB on its own (the SSD was running out of space).
  • HSWQ quantization protects critical layers in FP16 and can mix ConvRot INT8 with NVFP4; in that case the size becomes more than 50% of FP16, but precision improves.