When receiving 1 byte, benchmarking shows no visible difference with values
between 4096 and 65536 for the buffer size. With higher values, it becomes
significantly slower.

On the other side, a 64k buffer is faster with bigger packets.
Time to run testBasicStore with MySQL:

            4096        65536
    real    0m51.115s   0m21.592s
    user    0m41.857s   0m13.540s
    sys     0m8.700s    0m2.687s