Chunk 9.0

In this chunk, the assistant continued Phase 2 of the cuzk pipelined SNARK proving engine, focusing on E2E GPU testing, performance analysis, and planning the next implementation steps. The primary achievement was a successful end-to-end GPU test of the pipelined PoRep C2 path: the daemon was built with `--features cuda-supraseal`, started with pipeline mode enabled, and a 32 GiB PoRep C2 proof was submitted and completed. The proof was valid (1920 bytes, correct for 10 partitions × 192 bytes each), confirming that the bellperson fork, SRS manager, and per-partition synthesis/GPU pipeline all work correctly in a real GPU environment. However, the test revealed a critical performance issue: sequential per-partition proving (synthesize partition 0 → GPU prove partition 0 → synthesize partition 1 → GPU prove partition 1 → ...) took ~611 seconds total, compared to the monolithic Phase 1 baseline of ~93 seconds. The per-partition approach is ~6.6× slower for a single proof because it serializes work that could be parallelized (monolithic batches all 10 partitions in one rayon synthesis call and one supraseal GPU call). The assistant identified that per-partition pipelining is designed for throughput on a stream of proofs (overlap synthesis of proof N+1 with GPU proving of proof N), not single-proof latency. Consequently, the plan was adjusted to first add a batch-all-partitions mode for single proofs, then implement pipelined PoSt/SnapDeals synthesis, and finally add true async overlap across separate proof jobs. The todo list was updated accordingly, with the E2E GPU test marked complete and the batch-all-partitions fix now in progress.

The Crucible of Reality: How an E2E GPU Test Transformed the cuzk Phase 2 Pipeline Architecture 2370 words

Message Articles

Subagent Sessions