SFTPGo can easily saturate a Gigabit connection on low end hardware with no special configuration, this is generally enough for most use cases.
For Multi-Gig connections, some performance improvements and comparisons with OpenSSH have been discussed [here](https://github.com/drakkan/sftpgo/issues/69), some of them need upstream updates so there are not included in the SFTPGo released version (0.9.6) yet. To summarize:
- In current state with all performance improvements applied, SFTP performance is very close to OpenSSH however CPU usage is higher. SCP performance match OpenSSH.
- The main bottlenecks are the encryption and the messages authentication, so if you can use a fast cipher with implicit messages authentication, such as `aes128-gcm@openssh.com`, you will get a big performance boost.
- SCP protocol is much simpler than SFTP and so, the multi-platform, SFTPGo's SCP implementation performs better than SFTP.
- Load balancing with HAProxy can greatly improve the performance if CPU not become the bottleneck.
## Benchmark
### Hardware specification
**Server** ||
--- | --- |
OS| Debian 10.2 x64 |
CPU| Ryzen5 3600 |
RAM| 64GB 2400MHz ECC |
Disk| 3* Intel P4510 4TB RAID0 |
Ethernet| Mellanox ConnectX-3 40GbE|
**Client** ||
--- | --- |
OS| Ubuntu 19.10 x64 |
CPU| Threadripper 1920X |
RAM| 64GB 2400MHz ECC |
Disk| Samsung 960EVO 1TB |
Ethernet| Mellanox ConnectX-3 40GbE|
### Test configurations
-`Baseline`: SFTPGo version 0.9.6.
-`Optimized`: Various [optimizations](#Optimizations-applied) applied on top of 0.9.6.
-`Balanced`: Two optimized instances, running on localhost, load balanced by HAProxy 2.1.3.
- AES-CTR optimization of Go compiler for x86_64, there is a [patch](https://go-review.googlesource.com/c/go/+/51670) that hasn't been merged yet, you can apply it yourself.
- Use [minio/sha256-simd](https://github.com/minio/sha256-simd) to accelerate MAC (Message Authentication Code) computation. In this way the tested hardware will use `Intel SHA Extensions` for SHA256 computation. This will give a significant performance boost compared to `AVX2` extensions used with the Go's SHA256 implementation. This patch is now included in SFTPGo master branch.
- A new allocator for `pkg/sftp` which greatly improve parallel loads. We are discussing about this patch with `pkg/sftp` maintainers [here](https://github.com/pkg/sftp/pull/344).
