DeepSeek-V4.1-Flash

Trends

• Open-weight models diversify in architecture, modality, and size

Items

1. Sep 17

   DeepSeek's V4.1-Flash technical report

   The report details a Causal Encoder-Decoder that activates 16B parameters at decode but only 8B at prefill, and a CSA2-plus-FP4 KV-cache design that cuts the in-HBM footprint to 890 bytes per token, roughly a quarter of V4-Flash's.

2. Sep 10

   DeepSeek-V4.1-Flash

   A 552B-parameter MoE on a new Causal Encoder-Decoder architecture with a 1M-token context and native multimodal input, released with MIT weights; DeepSeek says it surpasses V4-Pro and will reroute the flagship's traffic into it on September 14.