fast-copy vs scp / SFTP
scp and SFTP move files one at a time, with protocol round-trips for each open, write and close. On a tree of thousands of small files that overhead dominates — transfers often crawl at 1–2 MB/s no matter how fast the link is. fast-copy uses the same SSH connection differently: it pipes one continuous tar stream through it, so the network sees a single large transfer instead of ninety thousand tiny ones. The remote side only needs the tar it already has — it even works on servers with SFTP disabled.
The measured difference
91,663 files (888 MB) pushed over a 100 Mbps LAN, streamed as six ~100 MB tar batches with no temp files on either side:
| Result | |
|---|---|
| fast-copy, local → remote | 2 m 07 s — ~3× faster than the SFTP-based transfer of the same tree |
| Dedup bonus | 46,951 duplicate files hard-linked remotely instead of re-sent |
For typical many-small-file trees, remote transfers land 3–5× faster than scp/SFTP. Methodology here.
Feature differences that matter
| fast-copy | scp / SFTP | |
|---|---|---|
| Wire pattern | one tar stream per ~100 MB batch | per-file round-trips |
| Duplicate files | sent once, hard-linked remotely | sent every time |
| Post-copy verification | every file, by hash | none |
| Remote → remote | relay through your machine | scp -3 (slow, no dedup/verify) |
| Re-running an interrupted job | unchanged files skipped via hash cache | starts over (scp), manual (sftp) |
| Works when SFTP is disabled | yes (plain ssh + tar) | no |
| Ships with every OS | no — one binary to download | yes |
When scp is still the better tool
Honest answer: one file, right now, to a box you'll never copy to again — scp file host: is unbeatable in keystrokes and is already installed everywhere. The gap only opens when file count grows. And if you need sub-file delta sync of huge files that change slightly, that's rsync territory, not scp's or ours — see fast-copy vs rsync.
Download fast-copy · SSH transfer examples: the SSH guide
Also compared: fast-copy vs rsync · fast-copy vs cp · fast-copy vs Robocopy · fast-copy vs FastCopy · fast-copy vs TeraCopy · full benchmark methodology