The fastest delta weight syncs in the world

Baseten rebuilt its delta weight sync path so the GPU weights themselves serve as the parent checkpoint, eliminating the ~770 GB CPU copy and cutting a GLM-5.3 sync from 36 seconds with a 6-second pause to 15 seconds with a 0.8-second pause. The new design uses a native decoder that keeps only nonzero XOR bytes, O(1) Adler-32 checksum corrections, and a separate CUDA-free helper process, and it frees host memory for KV cache offloading, raising cache hit rate from 2% to 92% and output throughput per GPU by 3.2x at concurrency 48 on AgentX. It also enables Kimi K3 RL rollout on two GB300 nodes, syncing an 8.4 GB delta in 75 seconds with a 4.1-second pause.