Sparse expert layers 42-62 were rebuilt as ModelOpt MXFP8 from the BF16 zai-org/GLM-5.1 checkpoint. The remaining sparse expert layers stay NVFP4.

Important: GLM-5.1 stores its MTP / next-token-prediction layer as model.layers.78.*. The FP8-PB-WO mixed base checkpoint had that layer in BF16, so this checkpoint transplants model.layers.78.* from lukealonso/GLM-5.1-NVFP4-MTP to keep the production NVFP4 MTP layer.

Build Sources

Base mixed checkpoint: /root/.cache/huggingface/hub/models--festr2--glm51-nvfp4-w4a16-fp8pbwo-l42-62-20260517/snapshots/e37f1787435d2b2c111a5f5eac924a556a06e257
BF16 MXFP8 source: /root/.cache/huggingface/hub/models--zai-org--GLM-5.1/snapshots/26e1bd6e011feb778d25ae34b09b07074139d92d
NVFP4 MTP source: /root/.cache/huggingface/hub/models--lukealonso--GLM-5.1-NVFP4-MTP/snapshots/78b7fe365f3905b4e0261a85182fefdbd5137989

Reproduction

The builder script is here:

https://github.com/local-inference-lab/quant-toolkit/blob/codex/glm51-mxfp8-converter-20260526/tools/patch_glm51_experts_mxfp8_from_bf16.py

Commit:

https://github.com/local-inference-lab/quant-toolkit/commit/6f406718271f45b1365abf388a00483b66067fd8

Exact reproduction command is documented here:

https://github.com/local-inference-lab/rtx6kpro/blob/master/models/glm5.1_mxfp8_checkpoint.md

Static Validation

Expected checkpoint structure:

text

model.layers.42-62.mlp.experts.* -> MXFP8
model.layers.78.*                -> NVFP4 MTP
other sparse expert layers       -> inherited NVFP4/mixed base state

Sample tensors:

text

model.layers.42.mlp.experts.0.gate_proj.weight
  shape: [2048, 6144]
  dtype: F8_E4M3

model.layers.42.mlp.experts.0.gate_proj.weight_scale
  shape: [2048, 192]
  dtype: U8

model.layers.78.mlp.experts.0.gate_proj.weight
  shape: [2048, 3072]
  dtype: U8

festr2/glm51-nvfp4-mxfp8-l42-62-bf16src-20260526

GLM-5.1 NVFP4 + MXFP8 L42-62

Build Sources

Reproduction

Static Validation

festr2/
glm51-nvfp4-mxfp8-l42-62-bf16src-20260526