Queue downloads and only load 1 file at a time. Ideal for sequential reading of files on HDD on NAS.

[porg]

Use case: On your NAS trigger multiple downloads (certain remote source files to certain local destination folders) and then let them download unsupervised most efficiently

Source: NAS with HDD serving these files (e.g. movie recordings from a wedding) via e.g. SFTP or SMB, accessed with Cyberduck

1.mov 2.mov 3.mov 4.mov 5.mov 6.mov 7.mov 8.mov 9.mov

Target 1: USB thumb drive of auntie Anna connected to my Mac

chatting/    dancing/   kids/   show/   speeches/  

Target 2: USB thumb drive of uncle Charles connected to my Mac

familyDoe/    familyDane/

User goals

• I initiate the file operations quite quickly — I achieve to queue all my desired downloads in 2min
  • 6 files into 3 different folders on auntie Anna's USB
  • 7 files into 2 folders that are sufficient for uncle Charles filing needs on his USB drive
  • I am only limited by the speed of my mind and my dexterity with drag and drop operations
• I leave the download unattended for the rest — This may take 60min, I don't mind
• I want that to happen as fast and efficient as possible.

General

• When you perform your file drag and drop operations from the Cyberduck window to the local file browser window (e.g macOS Finder) Cyberduck creates a list of file transfers.
• Cyberduck → Settings → Transfer: Controls how such a transfer list is processed.

Settings needed for use case: Do not exist in Cyberduck currently

Environment: Cyberduck 9.1.2 on macOS 15.2 Sequoia

Desired settings for use case: Download 1 file at a time.

• This is ideal when files 1, 2, 3 come from the same NAS from the same HDD.
• Because then each file can be read sequentially.

Current situation

• Whereas if 1, 2, 3 download in parallel (as it happens now) the disk heads have to constantly move between the current chunk of 1, then current chunk of 2, then current chunk of 3, within their time-slot or fill-next-buffer based multiplexing algorithm which facilitates the parallel download over the single network link.
• This parallel downloading does not utilize the strengths of the HDD (sequential reading) but instead suffers from its weakness (random access). It takes far longer in total.
• Also on a protocol level the parallelization is only an overhead, not a gain, for this particular LAN scenario.

Workaround: Not really

• I can initiate /NAS/wedding/1.mov → /Anna-USB-Drive/dancing/1.mov
  • Then let it run alone. Come back.
  • Trigger next transfer.
  • And so on.
• Highly inefficient and cumbersome.

[dkocher]

Detailed report ❤️ . What you are looking for is supposedly

• Limit the number of concurrent transfers and connections per transfer
• May want to disable segmented downloads as this causes disk I/O when concatenating the segments

[dkocher]

2. No redundant/alternative presence in the Settings

There is a default setting in Preferences → Bandwidth. That should probably move to Preferences → Transfers for better discoverability.

[dkocher]

1. UI rendering glitches in the transfer windows

Long standing issue in #10748.

[dkocher]

3. "Browser Connection" mode

Bandwidth control should apply to transfers in Use browser connection mode as well.

[dkocher]

Opened #16837 to configure transfer connection setting in Preferences → Transfers.

[dkocher]

If you start a second transfer, the transfer stats on the bottom flicker between the stats of transfer 1 and 2 constantly.

It would make sense to disable concurrency for file transfers using the browser connection. Opened #16838.