I assume 100 bytes is too small and can slow down larger file transfers with all of the writes, but something like 1MB seems like it may be too much. Does anyone have any sugge
One empirical test you can do, if you haven't already, is of course to use a sniffer (tcpdump, Wireshark etc.) and look at what packet sizes are achieved when using other software for up/downloading. That might give you a hint.