DeepSeek ends Open Source Week with 3FS, handing over the storage and inference stack behind V3/R1
DeepSeek open-sourced one production component per day from 24 to 28 February: FlashMLA, an MLA decoding kernel for Hopper reporting 3,000 GB/s memory-bound and 580 TFLOPS BF16 compute-bound on H800; DeepEP, the first open expert-parallel all-to-all communication library for MoE with native FP8 dispatch; DeepGEMM, an FP8 GEMM library with runtime JIT and no install-time CUDA compilation; DualPipe plus the EPLB expert-parallel load balancer; and the finale 3FS.
3FS is an MIT-licensed parallel file system for AI training and inference reporting 6.6 TiB/s aggregate read throughput on a 180-node cluster, 3.66 TiB/min on GraySort with 25 nodes, and 40+ GiB/s per client node for KV-cache lookups, with Smallpond as its data-processing layer. These are the pieces DeepSeek actually runs in production, published with the numbers rather than benchmark slides.
WHY IT MATTERS
The strongest release of the week is not weights but serving economics. Anyone building agents or a self-hosted inference stack got DeepSeek's licensed, production-tested kernels and file system for free, which sets a hard ceiling on what closed labs can charge for the same capability. The cost of self-hosting a frontier-adjacent open MoE is no longer gated by unpublished systems work.
