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Mamba-3 Inference-Optimized SSM

1 post · Mar 2026

What this trail covers

Mamba-3 is a new state space model (SSM) designed with inference efficiency as the primary goal. It features a more expressive recurrence formula, complex-valued state tracking, and a MIMO (multi-input, multi-output) variant that boosts accuracy without slowing down decoding. Mamba-3 SISO outperforms Mamba-2, Gated DeltaNet, and even Llama-3.2-1B (Transformer) on prefill+decode latency across all sequence lengths at the 1.5B scale. The team also open-sourced the kernels, built using a mix of Triton, TileLang, and CuTe DSL for maximum hardware performance. The architecture includes QKNorm for training stability, removes the short causal convolution by combining simple biases on B and C after BCNorm with the new discretization-based recurrence, and adopts interleaved MLP layers. The optional pre-output projection for Mamba-3 improves length generalization performance on synthetic tasks at the slight cost of in-context real-world retrieval tasks. Hybrid models combining linear layers with self-attention enable better retrieval compared to a vanilla Transformer.

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