DeepSeek V4.1-Flash: a 763B encoder-decoder MoE with 8B prefill, 16B decode, and native vision

[AINews] DeepSeek v4.1-Flash: 763B-P8B-D16B novel causal Encoder–Decoder architecture with vision marks the Return of the Whale

DeepSeek dropped V4.1-Flash on Sep 10. Despite the 4.1 label, Sebastian Raschka called it a V5-level rewrite. It's a 763B total-parameter MoE with a causal encoder-decoder split: 8B active for prefill, 16B for decode, yielding 1–2% sparsity and up to 8× smaller KV cache vs V4 Flash. Native vision is built in, and V4 Pro has been quietly retired. The post doesn't include benchmark tables but argues current evals miss the point—the real advance is context efficiency for long-running agents.

Why it matters: DeepSeek drops V4.1-Flash with a 763B causal encoder-decoder MoE, 8B/16B active params, 1%-2% sparsity, and vision. Sebastian Raschka says it should've been V5. This is a major domestic flagship architecture update with a cross-source cluster forming. HKR all hit. Not 90+ yet ...