PulseAugur
EN
LIVE 13:21:37

Blackwell GPUs show 61% performance drop on Qwen3.5 model

By PulseAugur Editorial · [1 sources] ·

A performance analysis by SemiAnalysis indicates that NVIDIA's Blackwell GPUs exhibit a significant 61% regression when running the SGLang Qwen3.5 397B model due to unsupported NVLink multicast for confidential computing. This issue specifically impacts the ability to efficiently distribute computations across multiple GPUs, hindering performance for large language models. AI

IMPACT This hardware limitation could slow down the deployment and efficiency of large language models on next-generation NVIDIA hardware.

RANK_REASON Analysis of hardware performance regression on a specific model. [lever_c_demoted from research: ic=1 ai=0.7]

Read on X — SemiAnalysis →

AI-generated summary · Google Gemini · from 1 sources. How we write summaries →

Blackwell GPUs show 61% performance drop on Qwen3.5 model

How we ranked this

Signal score
0 / 100
Composite score across the factors below. Higher = stronger signal that this story matters right now.
Newsworthiness bucket
Tool
Analysis of hardware performance regression on a specific model. [lever_c_demoted from research: ic=1 ai=0.7]
Source corroboration
Single-source cluster
Only one publisher covered this so far. Single-source stories can still rank when the publisher is high-authority, but they lack cross-source corroboration.
Topics
infra, model release
Editorial topic classification. Feeds into how the story surfaces on /topic/<slug> hub pages and into the per-entity coverage mix.
AI-industry relevance
High
Clearly on-topic for AI-industry coverage.
Story freshness
97 days old
Aged out of breaking-news scoring windows; ranking reflects the durable signal from the full source set.

Full methodology in our editorial standards.

COVERAGE [1]

  1. X — SemiAnalysis TIER_1 English(EN) · SemiAnalysis_ ·

    TRUTH SOCIAL: NVLink multicast is not supported on Blackwell "Confidential Computing" leading to 61% performance regression on SGLang Qwen3.5 397B according to

    TRUTH SOCIAL: NVLink multicast is not supported on Blackwell "Confidential Computing" leading to 61% performance regression on SGLang Qwen3.5 397B according to @verdacloud 's recent github ticket. NVIDIA's  "Confidential Computing" is complete slop as in addition Hopper's https:/…

RELATED ENTITIES

RELATED TOPICS