Improve BitTorrent Sync Speed on LAN

A number of factors can affect how quickly your files transfer between devices. One of the most significant is whether your other devices are connected "directly" (i.e. appear on the same LAN), or "indirectly" (relayed).
Generally speaking, "direct" connections are preferable as they are significantly faster than relayed connections. Therefore, the first step to improving sync speed would be to try and ensure that direct connections are established between your devices. If they all reside on the same physical local LAN, this shouldn't be a problem. However, if they are "remote", you could consider establishing a VPN in order to make your remote devices appear as though they're all on the same local LAN.
Once your devices all appear on the same LAN, follow the steps in the article "Can I force Sync to do local network (LAN) syncing only and not sync via the Internet?" to restrict syncing to your local LAN.
Next, if possible, assign static IPs to your devices, and then use the "pre-defined hosts" settings (again, these are per folder) to list your devices. At the same time, untick the "Search LAN" option. By doing this, Sync will then know exactly where to connect without having to spend time searching for other devices.

Make sure you've not set any upload/download rate limits in Sync, and set the advanced "rate_limit_local_peers" setting is set to "false"
Another advanced setting that can be set to "false" to potentially further improve transfer speed is the "lan_encrypt_data" setting.

If you have a more powerful device, you could also consider setting "disk_low_priority" to "false", and increasing the size of "recv_buf_size" and "send_buf_size" to get a further speed advantage.

One final thing that can improve overall performance of Sync is how fragmented your hard discs are. The less fragmented, the better nc indexing speed will be - so if you've not de-fragmented your drives for a while, it's worth doing! Corporate training in chennai