

Network hardware that cannot process big flows of data packets at a time will affect the speed of Sync. It also means that the more peers with high uploading speeds, the higher the downloading speed will be.

If there is a peer with a slow uploading speed, other peers will have low downloading speeds.

Check your firewall properties (it should not block incoming packets to Sync's listening port) and your NAT settings. Download/Upload Speed will be slower for many small files as when transferring a few large files.
