ruvector 2026: SymphonyQG — High-Performance Rust Vector Search with Co-Designed 1-Bit Graph Quantization
150-word summary: ruvector now ships SymphonyQG (SIGMOD 2025), the fastest single-machine approximate nearest neighbour (ANN) search system in Rust. It stores 1-bit vector sketches inline with graph edges and pads each vertex's degree to a SIMD batch boundary, so a single XNOR-popcount pass evaluates 32 neighbours without any random cache misses. Benchmarked on x86_64 Linux at D=128: 2.11× QPS over standard HNSW at matched 97.6% recall@10 (n=5K, ef=100), scaling to 4.14× at n=50K. Pure Rust, zero unsafe intrinsics — LLVM auto-vectorises the XNOR+POPCNT loop.
cargo build --release && cargo testgreen.
Every graph-based vector search engine (HNSW, DiskANN, NSG) suffers the same bottleneck: expanding a vertex during beam search requires loading each neighbour's full embedding from a random memory address. At D=128 (512 bytes per