An unset transformer_quant used to mean off (run the GGUF as-is), so the
hardware ladder only engaged when auto was explicitly chosen and the panel
showed Off as the default. Unset (or auto) now hands the decision to the
ladder: a dense-capable GPU gets at least int8, data-center silicon fp8,
falling back to the GGUF when the device, VRAM, family deny table or disk
cannot take it. An explicit none/off pins GGUF-as-is and is now
expressible in the API (previously only omission meant off, so pinned-off
and unset were indistinguishable); an explicit scheme pins that scheme.
The dense candidate also gains a free-disk gate: with auto as the default
the bf16 base download (up to ~40 GB) must never wedge a nearly-full
model-cache disk, so the candidate is dropped (GGUF build kept) when free
space cannot hold it plus a 10 GiB margin. Unprobeable disk passes.
Frontend: the Dtype select defaults to Auto (fastest for GPU), keeps Off
as an explicit choice, and sends none through instead of omitting it.
Suite: 622 diffusion tests green (default-load test rewritten to the new
contract, explicit-off short-circuit covered), CI-sim green.
resolve_dense_quant_candidate now passes fam.name to
select_transformer_quant_scheme so the policy's proposed scheme honors the
family deny table (qwen-image lands on int8 instead of proposing fp8 that
the execution path would refuse). Test stub updated for the new keyword.
The loader used to plan memory from the GGUF file size and only offer the dense
transformer-quant fast path when that plan was already resident, so on a card where
the GGUF forced offload the int8/fp8 build (roughly half the bf16 bytes, or exactly
the quantised size when a pre-quantized checkpoint exists) was never attempted.
diffusion_auto_policy.py is a pure decision layer: a bf16-resident component table
per family (transformer / text encoders / VAE, with base-repo overrides for the
multi-size families), per-scheme size factors with separate steady and transient
(build peak) numbers, and resolve_dense_quant_candidate which the loader now uses to
re-plan memory against the candidate artifact before settling for offload. The
engaged plan is adopted only when the dense build succeeds; the GGUF fallback keeps
its own plan.
Status now carries a resolved provenance record per Advanced control (value, source
auto or explicit, reason) so the UI can label backend decisions.
