---
id: pr-flashinfer-3113
repo: flashinfer-ai/flashinfer
pr: 3113
title: 'Fix: Extend b12x FP4 GEMM support to SM121 (GB10/DGX Spark)'
author: meena-at-work
date: '2026-04-20'
url: https://github.com/flashinfer-ai/flashinfer/pull/3113
source_category: upstream-code
architectures:
- sm100
- sm90
tags:
- arch_pipeline
- attention_kv
- blackwell
- fp4
- gemm_quant
- hopper
- nvfp4
- sm120
techniques:
- fine-grained-quantization
- pipeline-stages
- warp-specialization
hardware_features:
- blackwell
- fp4
- hopper
- nvfp4
kernel_types:
- attention
- gemm
- runtime
languages:
- cuda-cpp
- cute-dsl
captured_at: '2026-05-16'
status: merged
merge_sha: 06cb1b76489ec539983b9e1289e4f336dbe1b969
inclusion_reason: Inspect scale layout, accumulator type, tile/schedule choice, epilogue fusion, and partial-tile guards before deriving a candidate.
changed_paths:
- flashinfer/gemm/gemm_base.py
artifact_dir: evidence/pull-bundles/flashinfer/gh-3113
head_ref_oid: 70de56f0e192a085b99788d13bfaff8919013650
---
# Fix: Extend b12x FP4 GEMM support to SM121 (GB10/DGX Spark)

- Repository: `flashinfer-ai/flashinfer`
- PR: [3113](https://github.com/flashinfer-ai/flashinfer/pull/3113)
- Decision: `Inspect scale layout, accumulator type, tile/schedule choice, epilogue fusion, and partial-tile guards before deriving a candidate.`
- Reason: Inspect scale layout, accumulator type, tile/schedule choice, epilogue fusion, and partial-tile guards before deriving a candidate.

## Changed Paths

- `flashinfer/gemm/gemm_base.py`

## Evidence Bundle

`evidence/pull-bundles/flashinfer/gh-3113`
