The generic quantize_text_encoders pass only covers text_encoder.._3, so
HiDream's HEAVIEST encoder (Llama-3.1-8B TE4, 16.1 GB bf16) always stayed
dense. TE4 is assembled separately (hidream_te4_kwargs), so the fp8 path
now lives there: when the requested TE quant is layerwise fp8 and the
device/family qualify, TE4 prefers the hosted pre-cast checkpoint
(unsloth/HiDream-I1-Full-FP8, 8.6 GB) and falls back to dense-load-then-
cast; a mid-pass cast failure reloads a fresh dense encoder instead of
shipping partial state. The pre-cast loader and builder gain
config_subfolder/config_overrides for standalone encoder repos whose
config sits at the root and whose pipeline needs forward flags
(output_hidden_states/attentions).
Verified on B200: bit-identity 291 tensors (225 fp8, 0 mismatches),
hosted checkpoint engages through the real backend (marker + status fp8),
load 24.3 s vs 48.0 s dense, LPIPS 0.133 mean over 3 same-seed pairs vs
the dense-TE render (gate 0.25), non-black frames.
Two more findings from the hosted-TE GPU smokes:
- Module.dtype reports the first floating parameter, which after the
layerwise fp8 cast is the fp8 STORAGE dtype. Flux2 derives its prompt
embed and latent dtypes from encoder.dtype and feeds them to
randn_tensor, which has no fp8 kernel, so ANY flux.2 load with
text_encoder_quant=fp8 crashed at generation (pre-existing, runtime
cast included). The cast now swaps in a subclass whose dtype property
reports the compute dtype; forward behaviour is unchanged.
- The dense transformer_quant fast path assembles companions through
_assemble_pipe, which never received the pre-cast TE injection, so the
hosted encoder engaged on full-pipeline and GGUF builds but not on the
fast path. Threaded through like the other two branches.
Verified live on B200: qwen-image (full pipeline), flux.2-dev (GGUF picker
with int8 DiT prequant), ltx-2 (video backend) all engage the hosted TE,
render non-black, and report text_encoder_quant=fp8 truthfully.
qwen-image and flux.2-dev (diffusion) and ltx-2 (video) now resolve a
hosted pre-cast fp8 text encoder from their unsloth -FP8 repos:
- unsloth/Qwen-Image-FP8: Qwen2.5-VL-7B, 16.6 GB dense -> 8.8 GB
- unsloth/FLUX.2-dev-FP8: Mistral-Small-24B, 48.0 GB dense -> 24.7 GB
- unsloth/LTX-2-FP8: Gemma3-12B, 48.7 GB fp32 store -> 13.2 GB
Every checkpoint verified bit-identical to dense-load-then-cast
(729 / 585 / 1066 tensors, zero mismatches) and smoke-tested through the
real backends with the repo engagement marker. Tests cover the wired
entries, the resolver filenames, builder metadata weights_only survival,
and the idempotent re-cast.
Hermetic CPU coverage for diffusion_te_prequant: the checkpoint
filename convention, family-table resolution by scheme and component
with malformed entries skipped, resolution priority (path override,
hosted repo, none) and the fp8-only scheme gate, the checkpoint
validation matrix (wrong format, missing state_dict, wrong scheme,
wrong component, wrong or missing base_model_id) with base case
folding, the local-path allowlist refusal and missing-file fallback,
and the assembly injection gating (mode, hosted entry, device support,
family deny, load failure, successful injection). Also pins the
te_prequant_repos field on both family dataclasses and that no family
ships a hosted TE checkpoint until the campaign wires one.
