--optimize-concurrent-downloads[=true|false|A:B] Optimizes the number of
concurrent downloads according to the bandwidth
available. aria2 uses the download speed observed
in the previous downloads to adapt the number of
downloads launched in parallel according to the
rule N = A + B Log10(speed in Mbps). The
coefficients A and B can be customized in the
option arguments with A and B separated by a
colon. The default values (A=5,B=25) lead to
using typically 5 parallel downloads on 1Mbps
networks and above 50 on 100Mbps networks. The
number of parallel downloads remains constrained
under the maximum defined by the
max-concurrent-downloads parameter.
