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Figure 11: ZAYA1-8B · diagram by Sebastian Raschka · click to zoom
Sparse MoEZyphra 🇺🇸 · May 6, 2026

ZAYA1-8B (8.4B)

Zyphra's compact reasoning MoE pairs CCA/GQA attention updates with top-1 routed expert FFN updates to keep fewer than 1B parameters active per token.

Key detail

Key detail is CCA/GQA attention, which performs attention in a compressed latent space while keeping a 4:1 GQA layout. Sidenote: the config lists 80 alternating layer entries, equivalent to 40 CCA/GQA attention updates paired with 40 top-1 MoE FFN updates.

Total params

8.4B

Active / token

760M

Context

128K

Fact sheet

Scale
8.4B total, 760M active/token (9% active)
Context window
131,072 tokens
Decoder type
Sparse MoE
Attention
CCA with 4:1 GQA, RoPE, and Q/K L2 norm
Layer mix
40 CCA/GQA attention + 40 top-1 MoE FFN entries
KV cache / token (bf16)
40 KiB · Low
License
Apache License 2.0
Released

Efficiency

Parameters active per token

9.0%

760M of 8.4B weights run for each token.

KV cache per token (bf16)

40 KiB

Smaller than 69% of models in the atlas. How it’s calculated

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Similar architectures

  • Architecture diagram of GPT-OSS (20B)

    OpenAI, released 2025-08-04. Sparse MoE decoder, 21B total, 3.6B active, 128K context. Attention: GQA with alternating sliding-window and global layers.

  • Architecture diagram of Gemma 4 (26B-A4B)

    Google, released 2026-04-02. Sparse MoE decoder, 25B total, 3.8B active, 256K context. Attention: GQA with QK-Norm, unified K/V on global layers, p-RoPE on global layers, and 5:1 sliding-window/global attention.

  • Architecture diagram of Qwen3 (30B-A3B)

    Alibaba Cloud, released 2025-04-28. Sparse MoE decoder, 30B total, 3B active, 128K context. Attention: GQA.

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