rose-ash/lib/erlang/bench_ring_results.md

Ring Benchmark Results

Generated by lib/erlang/bench_ring.sh against sx_server.exe on the synchronous Erlang-on-SX scheduler.

N (processes)	Hops	Wall-clock	Throughput
10	10	907ms	11 hops/s
50	50	2107ms	24 hops/s
100	100	3827ms	26 hops/s
500	500	17004ms	29 hops/s
1000	1000	29832ms	34 hops/s

(Each Nm row spawns N processes connected in a ring and passes a single token N hops total — i.e. the token completes one full lap.)

Status of the 1M-process target

Phase 3's stretch goal in plans/erlang-on-sx.md is a million-process ring benchmark. That target is not met in the current synchronous scheduler; extrapolating from the table above, 1M hops would take ~30 000 s. Correctness is fine — the program runs at every measured size — but throughput is bound by per-hop overhead.

Per-hop cost is dominated by:

• er-env-copy per fun clause attempt (whole-dict copy each time)
• call/cc capture + raise/guard unwind on every receive
• er-q-delete-at! rebuilds the mailbox backing list on every match
• dict-set!/dict-has? lookups in the global processes table

To reach 1M-process throughput in this architecture would need at least: persistent (path-copying) envs, an inline scheduler that doesn't call/cc on the common path (msg-already-in-mailbox), and a linked-list mailbox. None of those are in scope for the Phase 3 checkbox — captured here as the floor we're starting from.