Data Transfers · Speed and advanced options
What does the Parallel transfers setting do?
Short answer: Parallel transfers is how many different files move at once within a transfer (1–32, default 8). Raise it for many small files on a fast link; lower it for slow connections. It doesn't speed up one big file.
Parallel transfers is how many different files move at the same time within one transfer, from 1 to 32. The default of 8 is a good balance for fast drives and connections.
- Raise it when you're sending lots of small files over a fast connection — more files in flight keeps it busy.
- Lower it (even to 1) to be gentle on a slow connection, a busy server or an older drive.
It doesn't speed up a single big file; that's what Streams per file is for.
Related: Streams per file · Why is my transfer slow?