---
id: pr-flash-attention-1173
repo: Dao-AILab/flash-attention
pr: 1173
title: FA3 FP8 qkv descales + restore max offset for h128 causal + added sync for producer WG
author: jayhshah
date: '2024-08-25'
url: https://github.com/Dao-AILab/flash-attention/pull/1173
source_category: upstream-code
architectures:
- sm90
tags:
- FA3
- arch_pipeline
- attention_kv
- benchmark_test
- fp8
- gemm_quant
techniques:
- async-copy
- fine-grained-quantization
- pipeline-stages
- warp-specialization
hardware_features:
- fp8
- hopper
- tma
kernel_types:
- attention
- gemm
- runtime
- softmax
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: c92ca63268836a6ea519e9892eda4895fc31811d
inclusion_reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.
changed_paths:
- hopper/benchmark_flash_attention_fp8.py
- hopper/flash.h
- hopper/flash_api.cpp
- hopper/flash_attn_interface.py
- hopper/flash_fwd_kernel.h
- hopper/flash_fwd_launch_template.h
- hopper/kernel_traits.h
- hopper/mainloop_fwd_sm90_tma_gmma_ws.hpp
- hopper/softmax.h
- hopper/test_flash_attn.py
artifact_dir: evidence/pull-bundles/flash-attention/gh-1173
head_ref_oid: a1576504e1017a7b2e7ae338c62fabd486846957
---
# FA3 FP8 qkv descales + restore max offset for h128 causal + added sync for producer WG

- Repository: `Dao-AILab/flash-attention`
- PR: [1173](https://github.com/Dao-AILab/flash-attention/pull/1173)
- Decision: `Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.`
- Reason: Preserve page/KV/layout and plan-run contracts; profile memory traffic separately from math utilization.

## Changed Paths

- `hopper/benchmark_flash_attention_fp8.py`
- `hopper/flash.h`
- `hopper/flash_api.cpp`
- `hopper/flash_attn_interface.py`
- `hopper/flash_fwd_kernel.h`
- `hopper/flash_fwd_launch_template.h`
- `hopper/kernel_traits.h`
- `hopper/mainloop_fwd_sm90_tma_gmma_ws.hpp`
- `hopper/softmax.h`
- `hopper/test_flash_attn.py`

## Evidence Bundle

`evidence/pull-bundles/flash-attention/gh-1173`
