CPU scaling benchmark
workers
1 +1 main
iters total
100M
50000000/stream
elapsed
453.66 ms
total CPU used
865.88 ms
speedup
1.91×
vs serial
efficiency
95.5%
of 2× ideal
| stream | spawn ms | spawned@ | work start@ | work end@ | work ms | reap wait ms |
|---|---|---|---|---|---|---|
| 0 (main) | 0 | 2.55 | 2.56 | 433.7 | 431.14 | 0 |
| 1 | 2.512 | 2.53 | 15.61 | 450.35 | 434.74 | 16.8 |
main
w1
fork+handshake
CPU work
parent reap wait
what this measures
Each stream runs a tight integer LCG loop — working set is one CPU register, no memory access,
no shared data. Speedup = sum(stream CPU time) / wall-clock elapsed. Efficiency = speedup / (workers+1).
100% efficiency means perfect linear scaling; less than 100% is the cost of serial fork setup,
reap tail, SMT/core contention.