[plug] file transfer performance linux/windows and filezilla

[Craig Ringer]

Denis Brown wrote:

> Am I expecting too much "performance" from the ssh layer during secure 
> file transfers?   To clarify...

Others have mentioned cyphers and compression. I thought I'd weigh in 
with some real numbers about their effects:

I can get 7.5 MB/s copying from my laptop (PIII-800, PC100) to the 
server (dual Xeon) over 10/100 at work.

	blowfish, no compression: 7.5MB/s
	blowfish, compression: 2MB/s
	3des, no compresion: 5MB/s
	3des, compression: 2MB/s

So, a few things that help:
	- Disable compression
	- Use a more efficient cypher than 3des.

My .ssh/config contains, among a lot of other things:

   Cipher blowfish
   Ciphers 
blowfish-cbc,aes128-cbc,3des-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc

... and I make sure not to enable compression for hosts on the local 
LAN. As you note later, you should be able to get almost 10MB/s on a 
10/100 network.

 > FileZilla set
> to non- or compressed mode makes no difference to transfer performance.

Odd. PuTTY might be worth trying, as others have suggested.

Also - do you need to force the NICs to full duplex? It might be an 
interesting experiment to leave them on auto-negotiation and see what 
happens. I've seen really weird problems caused by forced full duplex 
occasionally.

Craig Ringer