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models / compare / gpt-oss-120b-vs-inkling

gpt-oss-120b vs Inkling

How gpt-oss-120b (OpenAI, August 2025) and Inkling (Thinking Machines Lab, July 2026) are built, drawn on the same November 2026 blueprint. They make different choices on 12 of 27 components. Select a component in either diagram to find it in the table.

--- frontier-llm@2026-11+++ gpt-oss-120b@2025-08+0~4−9

gpt-oss-120b

OpenAI, August 2025, 117B total, 5.1B 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)Single residual stream — Residual & normSingle residual streamResidual & normRMSNorm — pre-normRMSNormpre-normQK-Norm — per-head RMSNorm on q, kQK-Normper-head RMSNorm on q, kFull RoPE with YaRN scaling — AttentionFull RoPE with YaRN scalingAttentionGated DeltaNet / KDA — linear · ~3 of every 4 layersGated DeltaNet / KDAlinear · ~3 of every 4 layersDense grouped-query attention — AttentionDense grouped-query attentionAttentionSparse / 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-normSoftmax top-k router — Mixture of expertsSoftmax top-k routerMixture of expertsRouted 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+++ inkling@2026-07+0~5−3

Inkling

Thinking Machines Lab, July 2026, 975B total, 41B 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)Single pre-norm residual stream — Residual & normSingle pre-norm residual streamResidual & normRMSNorm — pre-normRMSNormpre-normQK-Norm — per-head RMSNorm on q, kQK-Normper-head RMSNorm on q, kLearned relative-position bias (no RoPE) — AttentionLearned relative-position bias (no RoP…AttentionGated DeltaNet / KDA — linear · ~3 of every 4 layersGated DeltaNet / KDAlinear · ~3 of every 4 layersGlobal GQA with log-length scaling — AttentionGlobal GQA with log-length s…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 windowShort causal convolutions (SConv) — AttentionShort causal convolutions (SConv)Attention⊕ residual⊕residualRMSNorm — pre-normRMSNormpre-normSigmoid router with shared-expert sink — Mixture of expertsSigmoid router with shared-expert sinkMixture of expertsRouted 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

Component by component

gpt-oss-120b and Inkling differ on 12 of 27 components.

Blueprint componentgpt-oss-120bInkling

Not used

Same as the blueprintEncoder-free. Images and video are cut into 40 × 40-pixel patches, 2 frames deep. A 4-layer hierarchical MLP (three linear + RMSNorm + GELU stages that fold space and time into channels, then a linear projection) maps each patch to one 6,144-dim token. 16 kHz audio becomes dMel frames: 80 mel bins, each quantized to 16 levels, embedded by lookup and summed per frame.

Single residual streamOne d = 2,880 residual stream with pre-norm sublayers; no hyper-connections.

Single pre-norm residual streamOne d = 6,144 residual stream through 66 pre-norm blocks; no hyper-connections, branch outputs pass a short conv.

Not used

Same as the blueprintPer-head RMSNorm on q and k (head dim 128) in all 66 layers, applied to keys after their short convolution. Because q and k are normalized, the softmax scale is 1/d_h = 1/128 instead of 1/√d_h.

Full RoPE with YaRN scalingRotary embeddings on all 64 head dims, θ = 150,000, stretched 32× with YaRN.

Learned relative-position bias (no RoPE)Each head adds a bias by backward distance: a query-dependent mix of 16 learned profiles, over 512 (local) or 1,024 (global) tokens.

Dense grouped-query attentionFull causal attention with 64 query heads sharing 8 KV heads, in every other block.

Global GQA with log-length scaling11 full-attention layers (every 6th, incl. the last): 64 Q / 8 KV heads, d_h = 128; logits scaled up logarithmically past 128K.

Same as the blueprintNo output gate. Each head instead has a learned sink logit added to the softmax denominator, so it can assign attention mass to nothing.

Short causal convolutions (SConv)Depthwise causal convs (kernel 4, with skip) on K, V and on both sublayer outputs before they rejoin the residual.

Softmax top-k routerA linear router picks the top 4 of 128 experts; softmax over those 4 logits gives the weights.

Sigmoid router with shared-expert sinkScores 256 routed + 2 shared experts; bias-steered top-6; weights normalized jointly over the 8 active experts, then ×8.

Not used

Same as the blueprintTwo shared SwiGLU experts of intermediate size 3,072 run on every token. Unlike the blueprint's ungated shared expert, each is weighted by its own router score, normalized jointly with the 6 routed scores. They stay in BF16 in the NVFP4 checkpoint.

Not used

Same as the blueprint8 MTP layers ship in a separate file (mtp.safetensors). Each concatenates the previous hidden state with the next token's embedding and runs one decoder block with a dense MLP; MTP layers 1 and 3 use global attention, the other six sliding-window. Whether MTP was a pretraining loss is not stated.

Not disclosed

Same as the blueprintMuon for large matrix weights and Adam for all other parameters, with weight decay coupled to the square of the learning rate. Hyperparameter schedules draw on Thinking Machines' modular-manifolds research. Newton–Schulz settings are not published.

Not used

Same as the blueprintThe 8 MTP layers act as drafters for speculative decoding, verified by the full model so outputs match plain decoding. Thinking Machines has not published acceptance rates.

Not used

Same as the blueprintNo KV compression beyond the architecture: the released NVFP4 checkpoint leaves KV unquantized. The 11 global layers cost 44 KiB per token in BF16. The 55 sliding-window layers are capped at 512 tokens (about 220 MiB per sequence in BF16), plus small per-layer short-conv states.

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