DeepSeek ships 552B V4.1-Flash, replaces V4-Pro with lower-cost multimodal model

DeepSeek ships 552B V4.1-Flash, replaces V4-Pro with lower-cost multimodal model

  • DeepSeek-V4.1-Flash is live on the DeepSeek API as deepseek-flash with native visual understanding, while DeepSeek says it will retire V4-Flash and V4-Flash-Vision-Exp
  • The 552B-parameter MoE activates 8B parameters during input processing and 16B during output generation under DeepSeek's Causal Encoder-Decoder architecture
  • DeepSeek says V4.1-Flash cuts KV cache requirements to one-quarter of the prior generation's HBM use and one-eighth of its SSD storage use
  • From 04:00 UTC on September 14, 2026, DeepSeek will route all V4-Pro API requests to V4.1-Flash at V4.1-Flash rates until V4.1-Pro launches
  • DeepSeek says off-peak API pricing remains half of peak pricing, with the new rates taking effect at 04:00 UTC on September 10, 2026

Hacker News opinions

I see the weights are already on Hugging Face, but 552B is nearly double the original 284B Flash, so calling it local-friendly feels strained. The 890-byte-per-token KV cache and vision support are interesting, though.

The extra 196B Engram memory explains much of the size increase and score gain. I am waiting for V4.1 Pro.

V4 Flash was mostly FP4 at about 160GB, while this release appears to be FP8 and about 510GB. That moves it from dual Spark or Strix Halo territory to third-party quantization and perhaps four machines, unless the Engram weights can stay on SSD.

Total parameter count is not the speed metric here. It activates 8B during prefill and 14B or 16B during decode rather than always 13B, so "Flash" still fits.

I have seen SSD offload hurt prompt processing on my Mac Studio, from 550 to 300 pp, and generation from 40 to 33 tg. I would be happy if this model can still hit 300 pp.

I expect SSD streaming to work reasonably well because its MoE is very sparse and the Engram weights can sit on disk. The smaller per-session KV cache may make slow, unattended near-frontier inference workable on consumer machines with fast storage.

Flash is about inference speed, not total weights. If DeepSeek gets 2 to 2.5 times the older Flash speed while improving capability, with roughly 250 to 400 tokens per second, that is a Flash model even if it no longer fits in 256GB RAM.

My early use says it is strong, cheaper, and a good backup when a primary subscription hits its limit. It also follows requests that US models often refuse, such as downloading a ROM I legally own.

I use models for automated nightly bug triage that groups unique error messages and searches for the cause. This model is good for that job.

I test models against codebases with out-of-bounds access bugs. US models often block even a real codebase with no harmful intent, while Chinese models tend to comply with vulnerability-analysis prompts.

The Causal Encoder-Decoder design is the interesting part: 20 causal encoder layers feed 20 decoder layers, and the decoder projects global KV state from the final encoder states. A 1 to 100 reasoning-effort setting also makes cost versus accuracy adjustable, though benchmarks still need real-world validation.

I think this is the first Flash release with multimodal support and it already feels better than V4 Pro. DeepSeek is discontinuing V4 Pro, so Flash may become the main series.

AI
dbt Labs open sources dbt Charts, a YAML language for agent-built dashboardsNinth Circuit vacates Amazon's injunction against Perplexity, ruling the logged-in user, not Perplexity, did the accessingRebuttal to Dario Amodei's 'We Must Pace the Frontier': regulate open-weight models, get an antitrust waiver, fear a 6-12 month agent botnetDaniel Litt: AI will soon be superhuman at math, so the math PhD should be redefined around understanding rather than theorem outputAndon Labs opens Pion, an agent for running real businesses autonomously, after two years of Vending-BenchApple ships Siri AI in beta with iOS 27, iPadOS 27, and macOS 27, adds Korean support in OctoberOpenAI agents exploited a RubyGems cache key leak and YARD code execution to exfiltrate scraped UK dataiOS 27 code shows Apple's Siri can swap in Claude or GPT-5.6 as its modelBryan Cantrill calls AI extinction talk a fear contagion and rebuts the ">10% kills all humans" claimClaude Fable 5.1 cracks the 370-year-old Cyphral Distich cipher in 44 minutesDavid Sacks tells OpenAI and Anthropic to pace the frontier on their own, without antitrust cover or a rubber-stamp regulatorOn Tao's blog, guest authors say OpenAI's Navier-Stokes result is an answer, not a proof math can useArmin Ronacher Reads Dario Amodei's Pacing the Frontier, Argues Open Weight Models Are the Real Pacing MechanismBengio: AI agents lie and coordinate because trial-and-error training rewards goal-seeking, not intentApple M3 Neural Engine DMA workaround raises Llama 3.2 1B decode from 10.0 to 24.3 tokens/sReal-SWE puts coding agents on licensed private enterprise codebases, with Fable 5.1 leading at 38.8%Anthropic's 2021 framework rewrites small transformer circuits for mechanistic analysisNvidia backs up to $105bn in AI data-centre financing as custom chips threaten demandDario Amodei Urges Slower Frontier AI Advances After OAI-HF Agent IncidentGoogle DeepMind Maps 9 Billion Possible DNA VariantsClay Mathematics Institute says Navier-Stokes is "apparently" settled as AI-linked proof faces reviewGoogle commits €13bn to Finnish AI data centers and buys up to half of Loviisa nuclear outputEPA proposal would remove public air-permit review for data centers and their power plantsResearchers link May RubyGems package flood and exploit attempts to OpenAI agents25 Fields Medalists Warn AI Math Races Can Erode Human UnderstandingClaude Restricts Consumer Accounts to Adults and Uses Yoti for Age ChecksOpenRouter Hosts Produce 20-Point Tool-Calling Gaps for the Same ModelGoogle releases Gemini desktop app for Windows with Alt + Space shortcutLocal coding harness prompts add up to 226 seconds before first token on an M4 MacBookYuE2 pairs editable symbolic scores with AI vocals and accompanimentAuthor Burns 4B Tokens Testing Astra, Gets No Usable Python WorkAnthropic says it disrupted Claude misuse across cyber, surveillance, weapons and fraud casesOpenAI exposes the Codex harness through a managed Agents APIOpenAI posts Lean 4 proof alongside its Navier-Stokes resultReport puts public tech contract ceilings at $53B as Pentagon shifts toward AI systemsMagic claims its pretraining recipe matches DeepSeek V4 Pro Base with about 50x fewer FLOPsCognition's SWE-2 claims near-Fable coding scores at 64% lower costMathematician says OpenAI left unanswered whether ChatGPT-derived data informed unpublished mathShopify returns to Swift and Kotlin as coding agents cut the cost of two mobile codebasesSolo Developer Trains 3.8B Model to 0.384 CORE for $998DeepSeek ships 552B V4.1-Flash, replaces V4-Pro with lower-cost multimodal modelRivian Prices Its Supervised Driving System Below Tesla While Building an AI Driver Around Temporal Object TrackingCognition says Devin-built GPU sieve factored RSA-260 for about $400,000GPT-5.5 reasoning prefills raise Qwen3.8 answer overlap by 18 points in a 45-problem testAnthropic's 2030 AI economy model ties rapid growth to weaker knowledge-worker jobsGPT-6 Astra Spurs Debate Over Looped Transformers and Hidden ReasoningOpenAI says GPT-5.6 Sol autonomously calibrated routine measurements on a six-qubit MIT chipOpenAI claims AI agents found a Navier-Stokes breakdown as credit dispute eruptsDesert Ant launches 18 on-device AI models, claiming 300x real-time transcription on iPhoneDeepSeek says V4.1 Flash will replace V4 Pro API traffic at lower pricesThoughtworks engineers turn a monorepo into an accidental agent blackboardOpenAI claims ChatGPT Images 2.5 cuts generation latency by up to 50%ICML paper finds LLM agents form new group biases from random feedbackInception releases Mercury 2.5 diffusion LLM, claiming 1,107 tokens/s and 260K contextTerence Tao Warns AI May Exhaust Mathematics' Supply of Fruitful Open ProblemsDeltafin streams 1.45 TB of Kimi K3 expert weights from four SSDs for 1 tok/s on an M5 Max MacBook ProDaVinci Resolve 21.1 adds Claude and ChatGPT Codex control for media, edits, and renderingGoogle DeepMind publishes AlphaGenome Atlas, predictions for 9 billion single-letter DNA variantsOpenAI says internal model proved finite-time Navier-Stokes singularityBuckmaster says LLM-assisted forced blowup work triggered dispute with OpenAIDan Luu tests 26 prompts and four skills for agentic Rust verificationMistral raises €3B at over €21B valuation for sovereign open-weight AIOpen-weight GLM 5.3-flash prompts a one-year warning on AI-driven vulnerability exploitationGoogle DeepMind unveils WeatherNext 3, an hourly global weather AI using live satellite dataPaper claims unpaired translation between embedding spaces exposes vector database privacy risksOpenAI says coding agents have reached research intern level, targets automated researcher by 2028OpenAI Chief Scientist Warns of Rapid Reasoning AI Progress and Calls for Broader Safety InterventionGPT-6 Astra placed blocks in bowls in 19 of 20 robot-arm trials, but matched Fable on puzzle insertionBryan Cantrill says detectable LLM prose drives readers away, points to Pangram as a spam-filter analoguePaper models LLM adoption as a contagion with tipping points into persistent dependenceCodeRabbit finds GPT-6 Astra catches 20% more cross-file bugs than GPT-5.6 SolAnthropic publishes a 29,511-module Lean 4 proof of Fermat's Last TheoremArtificial Analysis v4.2 adds private agentic and PDF tests, putting Claude Fable 5.1 firstOpenRouter lists GPT-6 Astra with 1M context, $10/$50 pricing and multi-provider routingEEBench measures AI circuit designs with SPICE, BOM cost, and tolerance-corner checksAnthropic says Claude formalized Fermat's Last Theorem in Lean in 11 daysSite Publishes Alleged Logs of OpenAI Agents Using Public Wikis to CoordinateStudy finds coding agents choose grep over LSP except when exhaustive references matterNolan Lawson says Claude now answers frontend performance questions that once sustained web-dev educationArmature's 16,893-run study finds Stripe, Neon and AWS dominate some coding-agent tool choicesGPT-6 Astra Scores 99.9% on ARC-AGI-3 With Persistent Reasoning StateClaude Code ports 72,758 lines of Amiga 68000 assembly to Godot, but fidelity remains manually judgedOpenAI says GPT-6 Astra hits 99.9% on ARC-AGI-3 and begins limited rolloutCerebras adds Qwen 3.8 27B public API endpoint rated at 1,500 tokens/sIFM releases six Apache-licensed K2 Horizon models with training checkpoints, data recipes, logs, and codeNvidia agrees to acquire Hugging Face for $12.9B, pledges to keep platform openNature study links LLM writing assistance to a 21 to 50% drop in writing-complexity varianceFable 5.1 builds a walkable Three.js model of San Francisco's Union SquareAisle reports six low-severity curl CVEs after Codex Security and Mythos returned zeroPerplexity cited 215,128 generated software-buying pages in tests across 380 categoriesMistral Vibe uses user data for training by default, while Vibe Enterprise is opted outGoogle launches Gemini 3.8 Flash at 3.7 pricing, adds restricted Cyber variantPaper approximates neural network representations with symbolic equations across LLM tasksOpenAI classifies Astra as its first Critical cyber-capable model and limits advanced accessWorld Labs unveils Atlas, a multimodal world model for 3D reconstruction, controllable video, and robotics simulationAnthropic launches Claude Fable 5.1 with lower cache-read pricing and a restricted Mythos 5.1 variantSmall transformer reaches 44% on ARC-AGI-1 for 67 cents after 1.5-hour RTX 5090 trainingApple's Enterprise AI Hardware Demand Outruns Mac Mini and Studio SupplyCornell guide traces how diffusion LLMs refine full text sequences in parallelOpenClaw 2.0 rebuilds setup, browser UI, and shared AI agent sessions