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models / compare / deepseek-v4-vs-deepseek-v4-1-flash

DeepSeek-V4-Pro vs DeepSeek-V4.1-Flash

How DeepSeek-V4-Pro (DeepSeek, April 2026) and DeepSeek-V4.1-Flash (DeepSeek, September 2026) are built, drawn on the same November 2026 blueprint. They make different choices on 6 of 27 components. Select a component in either diagram to find it in the table.

--- frontier-llm@2026-11+++ deepseek-v4@2026-04+0~1−3

DeepSeek-V4-Pro

DeepSeek, April 2026, 1.6T total, 49B active

Text · code · tool outputText · code · tool outputImages · video · audioImages · video · audioByte-level BPE tokenizer — 128K–262K vocabByte-level BPE tokenizer128K–262K vocabVision / audio encoder — native ViT or encoder-free patchesVision / audio encodernative ViT or encoder-free patchesToken embedding — media embeds spliced in placeToken embeddingmedia embeds spliced in placeEngram n-gram memory — hashed 2–4-gram lookup (V4.1)Engram n-gram memoryhashed 2–4-gram lookup (V4.1)Residual streams — mHC: n = 4 mixed streamsResidual streamsmHC: n = 4 mixed streamsRMSNorm — pre-normRMSNormpre-normQK-Norm — per-head RMSNorm on q, kQK-Normper-head RMSNorm on q, kPartial RoPE / NoPE — rotate 64 dims, or nonePartial RoPE / NoPErotate 64 dims, or noneGated DeltaNet / KDA — linear · ~3 of every 4 layersGated DeltaNet / KDAlinear · ~3 of every 4 layersHeavily Compressed Attention (HCA) — AttentionHeavily Compressed Attention…AttentionSparse / compressed attn — DSA indexer · CSA / HCASparse / compressed attnDSA indexer · CSA / HCASliding-window attention — local · 128–1,024-token windowSliding-window attentionlocal · 128–1,024-token windowOutput gate + sink — σ(x·W_g) ⊙ o · learnable sinkOutput gate + sinkσ(x·W_g) ⊙ o · learnable sink⊕ residual⊕residualRMSNorm — pre-normRMSNormpre-normMoE router — σ / √softplus · bias balancingMoE routerσ / √softplus · bias balancingRouted experts — top-6–22 of 256–896 · SwiGLURouted expertstop-6–22 of 256–896 · SwiGLUShared expert — 1–2 · always activeShared expert1–2 · always active⊕ residual⊕residualFinal RMSNormFinal RMSNormLM head — untied · vocab logitsLM headuntied · vocab logitsMTP module(s) — predict t+2 … t+kMTP module(s)predict t+2 … t+kNext-token logitsNext-token logitsDraft tokensDraft tokensMuon optimizer — Newton–Schulz · QK-Clip · per-headMuon optimizerNewton–Schulz · QK-Clip · per-headFP8 → FP4 training — block-scaled FP8 · MXFP4/NVFP4 QATFP8 → FP4 trainingblock-scaled FP8 · MXFP4/NVFP4 QATLong-context extension — staged 4K → 1M · YaRNLong-context extensionstaged 4K → 1M · YaRNRL with verifiable rewards — GRPO family · async agentic RLRL with verifiable rewardsGRPO family · async agentic RLOn-policy distillation — reverse KL to specialist teachersOn-policy distillationreverse KL to specialist teachersSpeculative decoding — MTP self-drafting · DSparkSpeculative decodingMTP self-drafting · DSparkKV-cache compression — FP4 KV · cross-layer reuse · SSDKV-cache compressionFP4 KV · cross-layer reuse · SSD
AttentionMixture of expertsResidual & normInput & outputTraining & inferenceData flowResidual / skipAddedReplacedNot usedNot disclosed

--- frontier-llm@2026-11+++ deepseek-v4-1-flash@2026-09+0~3−1

DeepSeek-V4.1-Flash

DeepSeek, September 2026, 552B + 196B Engram total, 16B (8B in prefill) active

Text · code · tool outputText · code · tool outputImages · video · audioImages · video · audioByte-level BPE tokenizer — 128K–262K vocabByte-level BPE tokenizer128K–262K vocabVision / audio encoder — native ViT or encoder-free patchesVision / audio encodernative ViT or encoder-free patchesToken embedding — media embeds spliced in placeToken embeddingmedia embeds spliced in placeEngram n-gram memory — hashed 2–4-gram lookup (V4.1)Engram n-gram memoryhashed 2–4-gram lookup (V4.1)Residual streams — mHC: n = 4 mixed streamsResidual streamsmHC: n = 4 mixed streamsRMSNorm — pre-normRMSNormpre-normQK-Norm — per-head RMSNorm on q, kQK-Normper-head RMSNorm on q, kPartial RoPE / NoPE — rotate 64 dims, or nonePartial RoPE / NoPErotate 64 dims, or noneGated DeltaNet / KDA — linear · ~3 of every 4 layersGated DeltaNet / KDAlinear · ~3 of every 4 layersCED decoder attention (CSA2 over encoder-projected KV) — AttentionCED decoder attention (CSA2…AttentionCSA2 encoder layers (2× compression, Full + Reuse) — AttentionCSA2 encoder layers (2× comp…AttentionSliding-window attention — local · 128–1,024-token windowSliding-window attentionlocal · 128–1,024-token windowOutput gate + sink — σ(x·W_g) ⊙ o · learnable sinkOutput gate + sinkσ(x·W_g) ⊙ o · learnable sink⊕ residual⊕residualRMSNorm — pre-normRMSNormpre-normMoE router — σ / √softplus · bias balancingMoE routerσ / √softplus · bias balancingRouted experts — top-6–22 of 256–896 · SwiGLURouted expertstop-6–22 of 256–896 · SwiGLUShared expert — 1–2 · always activeShared expert1–2 · always active⊕ residual⊕residualFinal RMSNormFinal RMSNormLM head — untied · vocab logitsLM headuntied · vocab logitsDSpark drafter (trained after pretraining) — Input & outputDSpark drafter (trained after pretrain…Input & outputNext-token logitsNext-token logitsDraft tokensDraft tokensMuon optimizer — Newton–Schulz · QK-Clip · per-headMuon optimizerNewton–Schulz · QK-Clip · per-headFP8 → FP4 training — block-scaled FP8 · MXFP4/NVFP4 QATFP8 → FP4 trainingblock-scaled FP8 · MXFP4/NVFP4 QATLong-context extension — staged 4K → 1M · YaRNLong-context extensionstaged 4K → 1M · YaRNRL with verifiable rewards — GRPO family · async agentic RLRL with verifiable rewardsGRPO family · async agentic RLOn-policy distillation — reverse KL to specialist teachersOn-policy distillationreverse KL to specialist teachersSpeculative decoding — MTP self-drafting · DSparkSpeculative decodingMTP self-drafting · DSparkKV-cache compression — FP4 KV · cross-layer reuse · SSDKV-cache compressionFP4 KV · cross-layer reuse · SSD
AttentionMixture of expertsResidual & normInput & outputTraining & inferenceData flowResidual / skipAddedReplacedNot used

Component by component

DeepSeek-V4-Pro and DeepSeek-V4.1-Flash differ on 6 of 27 components.

Blueprint componentDeepSeek-V4-ProDeepSeek-V4.1-Flash

Not used

Same as the blueprintDeepSeek-ViT, trained from scratch: 32 layers, width 1,024, 16 heads, 14-px patches embedded by a linear projection, 2D-RoPE, RMSNorm and SwiGLU. A 3×3 pixel-unshuffle cuts visual tokens 9× before a 2-layer MLP projector maps them to 5,120 dims. Images only, up to about 1344×1344 px.

Not used

Same as the blueprintTwo Engram modules (196B parameters, FP8) at layers 1 and 14: n-gram orders 2–4, 8 hash heads per order, 2,048 dims per order, about 16M rows per head table. A sigmoid gate on each mHC stream's normalized dot product with its own key adds a shared value. The short causal conv was dropped. Rows are prefetched from host memory over RDMA.

Heavily Compressed Attention (HCA)Every 128 tokens pooled into one KV entry; dense shared-KV attention over all of them plus a 128-token window.

CED decoder attention (CSA2 over encoder-projected KV)Layers 20–39 take uncompressed global KV from the encoder's last hidden state and re-select with a hierarchical indexer.

Same as the blueprintCompressed Sparse Attention in 30 of 61 layers (even layers 2–60), interleaved with HCA. Each KV entry pools 8 overlapping tokens at stride m = 4 with a per-channel softmax. A lightning indexer (64 heads × 128 dims, ReLU scores weighted per head) keeps the top 1,024 entries, which the 128 query heads attend to together with the SWA entries.

CSA2 encoder layers (2× compression, Full + Reuse)Layers 2–19: KV pooled 2→1 and computed in only 3 of 18 layers; the rest reuse that KV and its top-512 selection.

Same as the blueprintOne MTP module (depth 1), unchanged from DeepSeek-V3: an extra block that combines the normalized next-token embedding with the trunk's normalized state and shares the embedding and LM head. Its attention is sliding-window only. Loss weight 0.3, lowered to 0.1 when learning-rate decay starts.

DSpark drafter (trained after pretraining)Three 128-token-window blocks draft 5 tokens per pass from the backbone's last 3 layers; no MTP loss in pretraining.

Not disclosed

Same as the blueprintServed with the DSpark drafter: 5 draft tokens per pass, with the verification length chosen per request from predicted acceptance and profiled throughput under current load. DSpark also accelerates RL and OPD rollouts.

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