The Multicore Server Challenge
LeaderboardThe RealWorld Conduit API on Postgres 18, any language, on one 8 vCPU / 16 GB box. Postgres runs on the same box, so every CPU cycle counts.
| Rank | Language | Best score | Fastest implementation |
|---|---|---|---|
| 1 |  Rust | 100,000 | rust-tokio-Scooter1337 · @Scooter1337 |
| 2 |  C# | 95,000 | csharp-sockets-jh-d · @jh-d |
| 3 |  C | 84,000 | c-iouring-tigokraft · @tigokraft |
| 4 |  COBOL | 84,000 | cobol-gnucobol-benmandrew · @benmandrew |
| 5 |  C++ | 68,000 | cpp-asio-c-hatton · @C-Hatton |
| 6 | Goose | 65,000 | goose-native-tbsvttr · @tbsvttr |
| 7 |  Go | 61,000 | go-epoll-o7livetype · @o7LiveType |
| 8 |  Kotlin | 46,000 | kotlin-vertx-canleon 🔒 · @canleon |
| 9 |  Python | 46,000 | python-uvloop-bensgilbert 🔒 · @bensgilbert |
| 10 |  Lua | 33,000 | lua-openresty-yar0slav 🔒 · @yar0slav |
| 11 |  Elixir | 32,000 | elixir-raw-foovoo 🔒 · @FooVoo |
| 12 | Pony | 25,000 | pony-stallion-contact-red 🔒 · @redvers |
| 13 |  D | 23,000 | d-arsd-cyrusmsk 🔒 · @cyrusmsk |
| 14 |  Java | 21,000 | java example 🔒 |
| 15 |  Swift | 20,000 | swift-hummingbird-denizakya 🔒 · @denizak |
| 16 |  V | 20,000 | v-fasthttp-ulises-jeremias 🔒 · @ulises-jeremias |
| 17 |  Bun | 18,000 | bun-native-PetarGeorgiev-hash 🔒 · @PetarGeorgiev-hash |
| 18 |  Perl | 1,100 | perl-mojolicious-denizakya 🔒 · @denizak |
Every language's best is public. Implementations outside the top 10 (🔒) open with the newsletter.
How it was run
The machine. 8 dedicated vCPU and 16 GB RAM, Ubuntu 24.04, with Postgres 18 on the same box. The load generator runs on a separate 16-core machine.
How each entry is scored. Every entry is built from source on the box and has to pass the 197-check conformance suite against the full seed. Virtual users browse like people (about 7 s between pages, sessions of about 15 minutes, 95% reads). After a 3-minute warm-up, two-minute runs double the users until one fails, then narrow down to within 5%. A 5-minute hold confirms the number, stepping down 5% until one passes. The score is the most users held for 5 minutes with p95 under 500 ms, p99 under 1 s and under 1% errors.