Bizuayeu/GLM-5.3-Flash-NVFP4-attn-lmhead-W4A16
NVFP4 BIZ AXL: GLM-5.3-Flash-NVFP4, attention + lm_head in W4A16
Short name: NVFP4 BIZ AXL (AXL: the attention projections and lm_head in W4A16). It is the published option of the serving stack NVFP4 BIZ (Bizuayeu/GLM-5.3-Flash-NVFP4-2x-DGX-Sparks-BIZ); this repository's name describes the contents and stays as it is. Cite a revision as "NVFP4 BIZ AXL (<revision>)".
A derived checkpoint of `nvidia/GLM-5.3-Flash-NVFP4`. The attention-side linears and lm_head, which NVIDIA leaves in BF16, are repacked weight-only to W4A16 NVFP4; every other tensor is byte-identical to the source. It is not an NVIDIA or Z.AI release.
Use it for generation-heavy serial work, Japanese prose in particular, on the two-node GB10 (DGX Spark class) setup of Bizuayeu/GLM-5.3-Flash-NVFP4-2x-DGX-Sparks-BIZ: decode is about 40% faster than the source checkpoint at the same draft depth, prefill is a few percent faster, and about 4.4 GiB less is loaded per rank. That saving is what pays for a second sequence: the setup's AXL example profile serves two active sequences from 6 GiB of KV per rank, accepted there for routine use on 2026-09-23 at up to about 200K tokens each. Do not use it where the pinned weights must be matched exactly (code, tool use): it is not lossless — teacher-forced NLL is 1 to 6% higher on three of four test corpora.
At a glance
Requirements
The pinned vLLM (385dce36) does not route these modules through its NVFP4 path on its own, and this checkpoint declares the KDA input projection as q_proj / k_proj / v_proj plus one merged in_proj_bfg_a (b, f_a, g_a) instead of vLLM's six-in-one in_proj_qkvbfg_a. Loading therefore needs the two source overlays that the setup repository ships in its `overlays/` directory:
An overlay pair belongs to one revision of this checkpoint (see Revisions); a mismatched pair fails at load. Plain vllm serve on this folder without the overlays does not start.
Loading
- With the setup repository (recommended): set
runtime.derived_checkpointin the server TOML —pathto this folder,requant_target = "l", and the two overlays with their SHA-256 — and start through its launcher, which verifies the overlays and the manifest before every launch. `examples/server.axl.example.toml` carries all of it, with prefix-page dedup and two active sequences; replace its paths, image IDs and node details. Details: server configuration. - Without it: copy the two overlays over the two files named above inside a vLLM
385dce36installation, thenvllm servethis folder; the declarations inconfig.jsonthen reach the declared modules.
Measured against the source checkpoint
Two GB10, TP=2, MTP depth 3, temperature 0. This checkpoint is the profile the setup's reference pair serves (the AXL example: this checkpoint, prefix-page dedup, two active sequences, 6 GiB of KV per rank), measured on 2026-09-23 with one request in flight unless the row says otherwise; rows not re-measured that night keep the value of 2026-09-22, dated. The source checkpoint is the setup's distributed defaults (one sequence, 3 GiB of KV per rank), 2026-09-22 unless dated. Medians of three runs; ranges and conditions are in the setup repository's benchmarks (1.8.0, 1.10.2 and 1.10.4 sections).
Quality, teacher-forced NLL on the setup's four fixed corpora (same inputs, the serving profile of 2026-09-25: two sequences, deterministic Inductor configs; the same on the setup's 1.12 and 1.13 images):
The earlier figures (2026-09-22, one-sequence profile before the setup's 1.12 launch-state fix) were 1.6645 / 2.0024 / 1.0031 / 0.6279.
Since the setup's 1.12.0 (deterministic Inductor configs on both ranks), every launch checked has computed in the same numerical state; before it, relaunches fell into one of three states that differed in how a near tie falls. The setup checks every launch after a switch (weight digest, decode check, kernel hashes on both ranks); see its validation. Decode speed under MTP depends on how predictable the text is (counting is faster than prose); the draft is the checkpoint's own MTP layer, no extra weights.
Revisions
License and notices
The weights are redistributed under the MIT terms stated by the NVIDIA model card and by the upstream Z.AI license; both notices are preserved (README.nvidia.md, and the Z.AI license text in the setup repository's LICENSES/). This repackaging adds no training data and no new terms. The conversion tool is Apache-2.0 and its license applies to the tool, not to these weights. No warranty; see the source model cards for intended use and limitations.
