---
id: pr-thunderkittens-141
repo: HazyResearch/ThunderKittens
pr: 141
title: Zero the initial accumulator before applying `HMMA.16816`
author: dfyz
date: '2025-08-07'
url: https://github.com/HazyResearch/ThunderKittens/pull/141
source_category: upstream-code
architectures:
- sm100
tags:
- matmul
techniques: []
hardware_features: []
kernel_types:
- gemm
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: b743973e5b95540907dd63c30baa7fd8488b94c6
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- kernels/matmul/educational/level_04.cu
artifact_dir: evidence/pull-bundles/thunderkittens/gh-141
head_ref_oid: f5dca41ff3ec0140de991957a5de928af4882979
---
# Zero the initial accumulator before applying `HMMA.16816`

- Repository: `HazyResearch/ThunderKittens`
- PR: [141](https://github.com/HazyResearch/ThunderKittens/pull/141)
- Decision: `Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.`
- Reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.

## Changed Paths

- `kernels/matmul/educational/level_04.cu`

## Evidence Bundle

`evidence/pull-bundles/thunderkittens/gh-141`
