GLM-5.3-EXL3-3.2bpw-Pollard-Smooth

GLM-5.3 — EXL3 3.2 bpw, Pollard method, SmoothQuant-folded, for four DGX Sparks

zai-org/GLM-5.3 (744B total / ~40B active MoE, glm_moe_dsa: 78 layers, 256 routed experts + 1 shared, top-8, MLA attention with a DeepSeek-style sparse indexer, one MTP layer) quantized from the bf16 release to an EXL3 trellis at 3.21 bits per weight, with SmoothQuant folded in first and the allocation chosen by exllamav3's budgeted allocator on in-domain calibration data. Sized to serve on four 128 GB DGX Spark (GB10) nodes at tensor parallelism 4 with the model's own MTP layer as the speculative draft.

What is in the box

292 GB in 46 safetensors shards plus one 144 MB eh_proj shard; quantization_config.json (exl3, version 1.4.8, target_bits_per_weight 3.2, average_bits_per_weight 3.21, head_bits 6, mtp_bits 8 — bits is kept as the integer 3 because the Hub's config validator requires an integer there); GLM-5.3 tokenizer and the updated upstream chat template (commit aca966e).

Measured quality (same fleet, same probes, same day; "int4 TP8" = our production int4/int8 GPTQ build of the same model)

Probes are teacher-forced or greedy through the served API. The perplexity texts were excluded from calibration by content hash.

Speed and memory (vLLM 0.28, TP4, fp8 KV, MTP k=3, --gpu-memory-utilization 0.84)

Serving

Built and measured with vLLM 0.28 plus an EXL3 runtime plugin that provides the sparse-MLA attention backend for GB10 and the EXL3 GEMM/MoE kernels (--attention-backend CUSTOM --block-size 256 --kv-cache-dtype fp8, speculative config method: mtp, num_speculative_tokens: 3, --max-model-len 180000).

Runtime requirement. This artifact quantizes attention and the head, which public expert-only EXL3 builds do not. The EXL3 runtime therefore has to (1) decode every fused shard at its stored width — exllamav3 pads output widths to multiples of 128 and applies a 128-column output Hadamard, so kv_a_proj_with_mqa is stored 640 wide for 576 declared — and trim afterwards, and (2) shard a quantized lm_head on 128-row boundaries of the global vocabulary under tensor parallelism. A runtime that narrows the trellis to the declared width, or starts a vocab shard mid-block, loads this model without error and emits gibberish. Check with a teacher-forced perplexity read before trusting it: the numbers above were taken on a runtime that satisfies both. NVFP4 KV is not available on the sparse-MLA path we used.

GLM-5.3's chat template has no enable_thinking switch. Control thinking with chat_template_kwargs {"reasoning_effort": "low" | "high", "clear_thinking": false}; passing chat_template_kwargs replaces the server defaults.

Recipe (short)

1. Streaming bf16 forward over 384 × 2048 in-domain rows with hooks on the two norm seams of each layer → per-channel max|x|; SmoothQuant fold at α = 0.5 (norm weight ÷ s, consumer columns × s). Exactly invertible.
2. exllamav3 1.4.8 (aarch64 build) budgeted allocator, -b 3.2 -hb 6 -mb 8 -hq, same calibration rows (-cd). No hand-tiered recipe: the allocator's choices beat ported per-layer recipes on this model (Pollard Weights' measurement, reproduced).
3. Band-parallel conversion on ten nodes (8 layers each, --resume from the previous band's hidden state, static strategy), merge, compile.
4. Restore bf16 eh_proj; resolve MTP-side tensors by shard headers, not the index.

The full recipe and receipts follow in a companion repository.

Files

model-00001…00046-of-00046.safetensors, model-mtp-eh_proj.safetensors, model.safetensors.index.json, config.json, quantization_config.json, generation_config.json, tokenizer.json, tokenizer_config.json, chat_template.jinja.

Prior work this build stands on

• GLM-5.3 — Z.ai. The model, its architecture, tokenizer, chat template and license. https://huggingface.co/zai-org/GLM-5.3
• Pollard Weights — WestWaters. The quantization method and playbook followed here: Hessian error-feedback quantization on in-domain calibration, MoE-aware allocation, the hf-smooth SmoothQuant fold, and the EXL3 lane with its measured finding that exllamav3's budgeted allocator beats hand-ported per-layer recipes. Our measurements from this run were contributed back (PRs #36, #39, #40). https://github.com/WestWaters/pollard-weights
• exllamav3 / EXL3 — turboderp-org. The trellis format, converter (v1.4.8) and budgeted allocator that produced these tensors. https://github.com/turboderp-org/exllamav3
• QTIP — Tseng, Sun, Ouyang, De Sa. QTIP: Quantization with Trellises and Incoherence Processing, NeurIPS 2024 — the trellis-coded quantization with Hadamard incoherence processing that EXL3 implements. https://arxiv.org/abs/2406.11235
• SmoothQuant — Xiao, Lin, Seznec, Wu, Demouth, Han. SmoothQuant: Accurate and Efficient Post-Training Quantization for Large Language Models, ICML 2023. https://arxiv.org/abs/2211.10438
• GPTQ — Frantar, Ashkboos, Hoefler, Alistarh. GPTQ: Accurate Post-Training Quantization for Generative Pre-trained Transformers, ICLR 2023 — the Hessian error-feedback rounding behind the int4/int8 comparison build. https://arxiv.org/abs/2210.17323
• cuda-exl3 — Zeuss5. vLLM plugin providing the GB10 sparse-MLA attention backend and EXL3 GEMM/MoE kernels the numbers above were measured on (v1.0.0). https://github.com/Zeuss5/cuda-exl3
• vLLM — vllm-project, v0.28.0. https://github.com/vllm-project/vllm — and the GB10 container lineage by ciprianveg (gb10-glm-5.2) our serving images derive from. https://github.com/ciprianveg/gb10-vllm
• drowzeys — keys-GLM-5.3-EXL3-Abliterated and its 4 × DGX Spark serving recipe: the first public four-node GLM-5.3 EXL3 build (experts 3.0 bpw, everything else bf16; TP4 DCP1, 200K, ~15 tok/s, KL 0.10 vs bf16), the baseline this build was measured against, and the source of two findings we confirm (context is nearly free, decode-context parallelism is the tax). https://huggingface.co/drowzeys/keys-GLM-5.3-EXL3-Abliterated · https://github.com/drowzeys/keys-GLM-5.3-EXL3-3.0BPW-abliterated-vLLm-cuda-Exl3
• Mia AI Lab — GLM-5.3-Flash EXL3 on 2 × DGX Spark: the vLLM + EXL3 container and sparse-MLA overlay that recipe serves from. https://github.com/MiaAI-Lab/GLM-5.3-Flash-EXL3-2x-DGX-Sparks
• 0xSero — GLM-5.3-500B-EXL3-3.0bpw: another public expert-only EXL3 build of this model. https://huggingface.co/0xSero/GLM-5.3-500B-EXL3-3.0bpw
• DeepSeek-V3 (multi-token prediction, the MTP layer used as the draft) https://arxiv.org/abs/2412.19437 and DeepSeek-V3.2 / DeepSeek Sparse Attention (the indexer + top-k sparse MLA that GLM-5.3's attention follows) https://github.com/deepseek-ai/DeepSeek-V3.2
• EvalPlus — Liu, Xia, Wang, Zhang. Is Your Code Generated by ChatGPT Really Correct?, NeurIPS 2023 — HumanEval+ / MBPP+. https://github.com/evalplus/evalplus

License / provenance

Derivative of zai-org/GLM-5.3 (GLM-5.3 License, © 2026 Z.AI). Quantization and measurement by bot-lab-21. Quantizer method: Pollard Weights (Apache-2.0); converter: exllamav3 (MIT); serving: vLLM (Apache-2.0) with the cuda-exl3 plugin. Produced with the help of an AI assistant operating the cluster.