---
id: pr-cccl-cub-8922
repo: NVIDIA/cccl
pr: 8922
title: Disable warpspeed scan on sm120 with nvcc < 13.4
author: bernhardmgruber
date: '2026-05-12'
url: https://github.com/NVIDIA/cccl/pull/8922
source_category: upstream-code
architectures:
- sm100
tags:
- blackwell
- block
- scan
techniques:
- warp-specialization
hardware_features:
- blackwell
kernel_types:
- scan
languages: []
captured_at: '2026-05-16'
status: merged
merge_sha: a9fa44cf5824ddffbed886964aab0282e61ec289
inclusion_reason: Search-matched CUDA kernel optimization PR; materialize diff/source before synthesis.
changed_paths:
- cub/cub/device/dispatch/tuning/tuning_scan.cuh
artifact_dir: evidence/pull-bundles/cccl-cub/gh-8922
head_ref_oid: 085d924bda0d80fa47667088fc859adf04d167e2
---
# Disable warpspeed scan on sm120 with nvcc < 13.4

- Repository: `NVIDIA/cccl`
- PR: [8922](https://github.com/NVIDIA/cccl/pull/8922)
- 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

- `cub/cub/device/dispatch/tuning/tuning_scan.cuh`

## Evidence Bundle

`evidence/pull-bundles/cccl-cub/gh-8922`
