Bandwidth limit and files at once
Advanced options in New Transfer let you cap a transfer's speed (for example 10M for about 10 MB/s), choose how many files move in parallel (1 to 32, default 8) and how many streams fetch one large file (1 to 16, default 4).
Advanced options, at the bottom of the New Transfer sheet, control how hard a transfer pushes: a Bandwidth limit caps its speed, Parallel transfers sets how many files move at the same time, and Streams per file splits one large file into several pieces fetched together. The defaults suit most connections, so you only need these when a transfer is slowing other things down or a big file is slow to arrive.
The settings
| Setting | What it controls | Range | Default |
|---|---|---|---|
| Bandwidth limit | The top speed for this transfer | Any value, or empty | Empty, meaning no limit |
| Parallel transfers | How many different files move at the same time | 1 to 32 | 8 |
| Streams per file | How many pieces of one large file are fetched at the same time | 1 to 16 | 4 |
Parallel transfers is the "files at once" setting. It isn't shown when you choose Download, because a download is a single file and the setting can't speed it up.
Writing a bandwidth limit
Type a number followed by a letter:
10M— about 10 megabytes a second (roughly 80 megabits a second). Use a capital M for megabytes.100k— about 100 kilobytes a second. Use a lowercase k for kilobytes.- Leave it empty for no limit.
The limit applies to the transfer as a whole, not to each file. A transfer's details show its limit under Bandwidth, or Unlimited if there isn't one.
Choosing values
- Your internet feels slow while a transfer runs: set a Bandwidth limit below your connection's upload or download speed, or lower Parallel transfers.
- Many small files, such as photos or documents: the default of 8 parallel transfers is a good balance. More can help on a fast connection to a fast service.
- A slow or shared connection: drop Parallel transfers to 1 to be as gentle as possible.
- One very large file: Parallel transfers won't help. Raise Streams per file instead — more streams are usually faster until the server or your connection becomes the limit. Only larger files, roughly above 256 MB, are split into streams.
Flowchart outline: Which advanced setting to change
- What's the problem?
- Other apps or people slowed down: leads to Set a Bandwidth limit or lower Parallel transfers
- Lots of small files feel slow: leads to Raise Parallel transfers
- One huge file feels slow: leads to Raise Streams per file
- Nothing, it's fine: leads to Leave the defaults
Things to know
- Settings are fixed for a transfer once it starts. Sync again, Run again and scheduled runs reuse the same values. To change them, set the transfer up again from New Transfer.
- Up to two transfers run at the same time. Others wait as Queued, so the limits you set apply per transfer, not across all of them.
- Scheduled runs are already gentle. They run in the background at low priority so your own work comes first, whatever you set here. See Scheduling a transfer.
- Some services limit how fast an app may go. If a cloud account starts refusing requests because of its own limits, fewer parallel transfers can help. See A transfer failed.
See also: Data Transfers · Copying between two cloud accounts · Why Storage Studio works slowly on purpose