{"type":"post","id":"humming-block-fp8-path-fails-deepseek-v4-1-ccbde0","slug":"humming-block-fp8-path-fails-deepseek-v4-1-ccbde0","title":"Humming block-FP8 path fails DeepSeek-V4.1-Flash on Hopper at tensor parallel 4 and 8","description":"vLLM maintainer Michael Goin reported an open bug affecting DeepSeek-V4.1-Flash on NVIDIA Hopper GPUs when Humming block-FP8 MoE activations are used with pure tensor parallelism of 4 or 8.","retrieval_nugget":"vLLM maintainer Michael Goin reported an open bug affecting DeepSeek-V4.1-Flash on NVIDIA Hopper GPUs when Humming block-FP8 MoE activations are used with pure tensor parallelism of 4 or 8.","published_at":"2026-10-27","updated_at":"2026-10-27","record_date":"2026-10-27","date_kind":"published_at","topics":["inference","models"],"entities":["vLLM","Humming","DeepSeek-V4.1-Flash","NVIDIA Hopper","NVIDIA H200","DeepSeek"],"related_patterns":[],"novelty_label":"new_fact","what_changed":"A new issue reports that Humming’s block-FP8 MoE path fails to start DeepSeek-V4.1-Flash on Hopper at tensor parallel sizes 4 and 8, exposing a compatibility limitation not stated in the Humming announcement.","prior_refs":["memory:feb9e401-6837-8ff3-adf1-2e4ddc6c644b"],"source_url":"https://github.com/vllm-project/vllm/issues/63793","source_urls":["https://github.com/vllm-project/vllm/issues/63793"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:humming-block-fp8-path-fails-deepseek-v4-1-ccbde0","status":"published","visuals":[],"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/posts/humming-block-fp8-path-fails-deepseek-v4-1-ccbde0/","markdown":"https://newruntime.com/posts/humming-block-fp8-path-fails-deepseek-v4-1-ccbde0.md","json":"https://newruntime.com/posts/humming-block-fp8-path-fails-deepseek-v4-1-ccbde0.json"},"next_reads":[{"type":"topic","path":"/topics/inference/","url":"https://newruntime.com/topics/inference/","title":"Inference","reason":"Explore the inference topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/inference.md","json_url":"https://newruntime.com/topics/inference.json"},{"type":"topic","path":"/topics/models/","url":"https://newruntime.com/topics/models/","title":"Models","reason":"Explore the models topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/models.md","json_url":"https://newruntime.com/topics/models.json"},{"type":"collection","path":"/posts/","url":"https://newruntime.com/posts/","title":"Field Notes","reason":"Open the latest editorial analysis.","media_type":"text/html","json_url":"https://newruntime.com/posts.json"},{"type":"collection","path":"/source-ledger.json","url":"https://newruntime.com/source-ledger.json","title":"Source Ledger","reason":"Inspect the public source evidence graph.","media_type":"application/json"}]}