Performance & Benchmarks

Results from v0.6.2 · Criterion · Dell Latitude 7490 · i7-8650U · Linux

Single-Thread (100K ops)

Where PulseMap Wins

Eviction-heavy workloads — PulseMap’s core strength. Eviction metadata lives in the same 64-byte cache line as data slots, so eviction decisions cost zero additional cache misses.

• 1.7x faster than quick_cache on eviction
• 29x faster than moka on eviction
• 3.1x faster than lru on insert

Where PulseMap Loses

Pure lookup — PulseMap stores values as serialized bytes (enabling no_std + FFI bindings), which adds deserialization cost on read. Note: AtomicU64 lock-free reads and AccessBuffer narrowed the gap on concurrent lookups in v0.6.2.

• quick_cache lookup: 1.5x faster than PulseMap
• lru lookup: PulseMap is now faster (4.2 ms vs 5.4 ms)

Multi-Thread — 4 Threads, 100K ops

ShardedPulseMap Advantage

ShardedPulseMap uses 16 independent shards with separate locks. This eliminates the global RwLock bottleneck in ConcurrentPulseMap.

• 2.3–3.9x faster than ConcurrentPulseMap
• 6.5–12x faster than moka on concurrent workloads

vs std::HashMap (reference only)

HashMap has no eviction — it’s a different category entirely:

Memory Efficiency

Running Benchmarks

# All benchmarks
cargo bench

# Specific category
cargo bench -- insert
cargo bench -- "4t"        # 4-thread benchmarks
cargo bench -- moka        # moka comparison
cargo bench -- sharded     # ShardedPulseMap only
cargo bench -- eviction

# With SIMD (x86_64 only)
cargo bench --features simd

Cache Line Efficiency

L1 cache hit rate during lookup:

PulseMap:   ~98% (1 cache line per lookup)
HashMap:    ~60% (2-3 cache lines, pointer chasing)
BTreeMap:   ~40% (tree traversal, multiple lines)

Profiling Tips

# CPU cache analysis with perf
perf stat -e cache-misses,cache-references cargo bench

# Flamegraph
cargo install flamegraph
cargo flamegraph --bench benchmark

# Valgrind memory analysis
valgrind --tool=cachegrind target/release/examples/basic

Bottlenecks & Limits