sftp transfer speed?

haquangbach · n00b Joined: 24 Sep 2004 Posts: 5

I use one machine to connect to my box which is running sftp (using OpenSSH). Both machines are in the same LAN. However, the transfer speed is just 640Kbps which seems not right to me. Since we're in the same LAN, transfer speed can be reach up to 10Mbps. I think there's a problem with configuration of the sftp service. But how can I change it?

bone · Posted: Fri Oct 22, 2004 2:19 am Post subject:

sftp uses the ssl encryption scheme to transfer things securely. On the average, most encrypted transmissions are slower than unencrypted transmissions. I have encountered this using scp as well.

Jon

adsmith · Veteran Joined: 26 Sep 2004 Posts: 1386 Location: NC, USA

if you want to test transfer speed, emerge iperf.

fleed · l33t Joined: 28 Aug 2002 Posts: 756 Location: London

Try this:
1) Start transfering a large file over sftp (one that'll take abou 30s at least)
2) While that is transferring check the cpu utilization on both machines involved in the transfer (use top for that)

If either of the machines is highly loaded you've just found out why it can be quite pointless to do large file transfers over your own lan using encryption. If you're using scp you can try specifying a light-weight cypher such as blowfish.

Thisp · n00b Joined: 29 Jul 2006 Posts: 46

I am having the same issue. I tried it with LAN transfer just out of curiousity and I got 1.5 mbps.. same as WAN transfer with it. I'm thinking 1.5 mbps is hardcoded somewhere for it since I can get up to 9.5 with vsftpd on WAN and 350 mbps on LAN.

SFTP uses 0-2% CPU in top.