$n$ (millions) 1 2 4 8 16
Average time (s) $6.9 \pm 0.3$ $13.8 \pm 0.2$ $31.9 \pm 0.7$ $69.9 \pm 1.1$ $140.6 \pm 2.5$
SD $0.4$ $0.2$ $0.9$ $1.5$ $3.5$
$n$ (millions) 32 64 128 512 1000
Average time (s) $284.3 \pm 1.1$ $587.9 \pm 3.9$ $1223.6 \pm 4.9$ $5966.4 \pm 9.5$ $13229.5 \pm 12.7$
SD $1.6$ $5.5$ $6.8$ $13.2$ $18.6$