keys-GLM-5.3-EXL3-2.75BPW

Full GLM-5.3 (753B, glm_moe_dsa) quantized to EXL3 with a per-expert mixed bit width averaging 2.75 bpw on the routed experts, sized to serve on four NVIDIA DGX Sparks (GB10, 128 GB unified memory each) with room for a 200K-token KV pool (or 1M tokens with decode-context-parallel 4).

Unmodified weights of zai-org/GLM-5.3 (no fine-tuning, no edits), quantized from the BF16 checkpoint. For the earlier uniform-width quant see keys-GLM-5.3-EXL3.

Run it: TensorFold on four DGX Sparks (recommended)

The fastest way to serve this checkpoint is TensorFold's native glm_moe_dsa engine — tensor parallel 4, one rank per Spark, no vLLM in the serving path; a drafted reply equals a serial one. Recipe, one-shot launcher, benches and an AGENTS.md for coding agents: drowzeys/keys-TensorFold-GLM-5.3-TP4-4x-DGX-Spark. Code: drowzeys/TensorFold:glm53-tp4-2026-10-05. The default needs no extra draft model (GLM-5.3's own MTP layer drafts); DFlash2 is optional.

Performance (prebuilt image 2026-10-05, thinking on)

Four DGX Sparks, the published image through one-shot.sh, default settings, thinking on (GLM-5.3 is a reasoning model: measured the way it is meant to be used; no thinking-off numbers are published).

Prompt reuse: an identical resend 0.15 s, a new conversation with the same 14.7K-token system prompt 0.38 s (13.5 s without); at 4 x 32K turn 2 in 0.69 s. Agent frameworks (Hermes, OpenClaw): PARALLEL=4 CONTEXT=32768, agent context 64K, compression under 32K: each agent step starts in ~0.15-1 s instead of ~16 s.

Memory safety on GB10 is part of the recipe (vm.swappiness=1, shards dropped from the page cache as they load, one-shot.sh drops page cache and waits for memory to come back between lanes, and reports each node's headroom): ~9-15 GB free on every Spark while serving, no swap. Details in the recipe README.

Bertholomus' four tf_greedy.py prompts, thinking on: MTP 41.1 / 40.8 / 43.1 / 42.6, DFlash2 48.6 / 52.0 / 50.4 / 53.6 tok/s (their published MTP-3 numbers, thinking off, on their 3.0 bpw quant: 34.6-39.6 / 40.6-48.1 / 42.1-48.4 / 38.1-43.6). Optional DFlash2: incoai/GLM-5.3-DFlash2 (CC BY-NC-ND 4.0, download it yourself).

Quick start

# every Spark, after each boot (node/gb10-node-settings.sh in the recipe repo)
sudo sysctl -w vm.compaction_proactiveness=0 vm.swappiness=1
# the checkpoint at the same path on all four (an NFS export works; each rank reads only its share)
hf download drowzeys/keys-GLM-5.3-EXL3-2.75BPW --local-dir /models/GLM-5.3-EXL3-2.75BPW
# from any machine that can ssh to the four Sparks (one-shot.sh from the recipe repo)
export NODES="spark1 spark2 spark3 spark4" MODEL=/models/GLM-5.3-EXL3-2.75BPW
./one-shot.sh check && ./one-shot.sh up && ./one-shot.sh wait && ./one-shot.sh bench

Image ghcr.io/drowzeys/keys-tensorfold-glm53-tp4-dgx-spark:2026-10-05 (also :latest; CUDA 13 / GB10, extensions prebuilt, fastest settings as defaults). The launcher finds each Spark's RoCE rails and GIDs itself; an OpenAI-compatible server comes up on rank 0, port 8890. With DRAFT=<DFlash2 dir> requests can pick "tf_mtp": "dflash" (fastest on code) or "auto"; 4 streams: PARALLEL=4 CONTEXT=32768.

Build your own draft (optional)

An on-policy fine-tune of the DFlash2 draft on this checkpoint's outputs gave +10.5 % prose / +7.8 % code at 32K on our 2026-10-03 build. It cannot be published (incoai's CC BY-NC-ND-4.0 license); draft-finetune/ builds your own for non-commercial use.

What is in it

• 81 safetensors shards, 258 GB. kv_a_proj_with_mqa is stored 640 wide (576 real outputs + zero padding to the 128-column tile).
• Per-expert widths are listed in quantization_config.json (expert_bits, format keys35-v1); the allocation gives more bits to experts whose quantization error hurt the layer output most (measured on calibration activations).
• KEYS35_ASSEMBLY_REPORT.json records the assembly checks.

Quality

Alternative: vLLM, tensor-parallel 4 across four DGX Sparks (batched serving)

This checkpoint needs EXL3 support that stock vLLM does not have yet. Our serving image (not yet public) is vLLM with:

• exllamav3 1.5.0 kernels; a patched cuda-exl3 exl3_moe_gemm that accumulates into its output (out=);
• an exl3_mixedk MoE method: experts grouped by width for prompt chunks, and for decode windows (≤ 32 rows) TensorFold's universal EXL3 experts kernel (one launch per projection, a width per expert; vendored at v0.3.6.3 with a row-stride patch);
• an exl3_dense linear method for the 5-bit non-expert layers;
• MTP speculative decoding (k = 2), FULL CUDA graphs, fused all-reduce + RMSNorm, and a RoCE one-shot all-reduce for decode-sized messages (VLLM_ROCE_ALLGATHER_MAX_SIZE=4MB; larger messages stay on NCCL).

Key settings (TP = 4): --kv-cache-dtype fp8 --max-model-len 200000 --max-num-seqs 8 --kv-cache-memory-bytes 14092861440 --async-scheduling --compilation-config.pass_config.fuse_allreduce_rms=true --cudagraph-capture-sizes 1 2 3 4 6 8 12 24 --speculative-config '{"method":"mtp","num_speculative_tokens":2}'. Weights take 67.5 GiB per rank.

Measured on 4 × DGX Spark (single stream, 32K-token context, temperature 1.0, top-p 0.95, 512 tokens)

Prompt processing (200K profile): 749 tok/s at 4K, 733 at 32K, 668 at 128K tokens (TTFT 195 s at 128K). The 1M profile passed a needle at 128K (409 tok/s prefill at 32K). Prefill is the open problem: we expect it can reach ~2× this (rank skew in the all-reduce and the MoE prefill kernel are the two measured causes).

6-bit output head (optional, added 2026-10-12)

lm_head-6bit/lm_head-6bit.safetensors (714 MB) is lm_head.weight quantized to EXL3 at 6.0 bits with exllamav3 (tensors lm_head.trellis, lm_head.suh, lm_head.svh, lm_head.mul1). The checkpoint's own lm_head.weight stays bf16 and nothing else in the repository changed.

The 2026-10-12-mlx-serve image of the recipe reads the head from this file when it is in the checkpoint folder (hf download puts it there), and from the bf16 tensor when it is not or with HEAD_Q=off. Measured on four DGX Sparks, as served, against the BF16 checkpoint over 137,490 positions:

Other engines ignore the folder.

Credits

• Z.ai — GLM-5.3.
• Ash Hart / TensorFold and the TensorFold contributors (Apache-2.0; earlier code MIT) — the engine, its EXL3 kernels and the glm5_next family the serving engine builds on.
• MiaAI-Lab (Apache-2.0) — GLM prompt-kernel designs and the decode, sampling, stop, rail, rank-check and prompt-reuse patches adapted here.
• Jay Leaton (Apache-2.0) — the L2 prefetch and trellis-load work behind MiaAI-Lab's 0046 / 0047.
• BertholomusAI (Albert Lee) (Apache-2.0) — decode side stream, MTP index reuse, concurrent-stream draft cut and warm-up capture (ideas re-implemented), head-to-head prompts.
• turboderp / ExLlamaV3 (MIT) — EXL3; vcruz305 — the per-expert mixed-width EXL3 work this quantization builds on; cuda-exl3 — the grouped prompt GEMM.
• b12x (Apache-2.0) — RoCE one-shot collectives.
• incoai — the optional DFlash2 draft (CC BY-NC-ND 4.0, not redistributed).
• NVIDIA — DGX Spark, CUDA, NCCL; Anthropic's Claude (Claude Code) — engineering assistance.

Use is subject to the GLM-5.3 license of the base model.