openssh: why difference in transfer speed?

[sftpfilecontrol]

Using sftp on openssh, I notice consistently my download speed (from server to desktop) is about twice as fast as the upload speed.

Anyone know why this is?

--
mike

[coopstah13]

probably depends on the encryption engine being used on server vs desktop, and also the specs of the server vs the desktop

btw, is this upload over internet? if so, usually internet upload speeds are much lower for home internet access

[sftpfilecontrol]

probably depends on the encryption engine being used on server vs desktop, and also the specs of the server vs the desktop

btw, is this upload over internet? if so, usually internet upload speeds are much lower for home internet access

This is on a local LAN. It can't be the encryption engine because encryption goes both ways.

This is something I've noticed many times over several years on different servers and different networks. I'm just curious as to the reason and whether or not it's a configurable/tunable thing.

[coopstah13]

I'm not exactly sure, but it could be an implementation detail for the file transfer itself and a discrepancy between machine power

When you upload, you have to encrypt before you upload, so this will require the CPU while uploading, but perhaps when downloading, you can just run encryption at the end, rather than decrypting while downloading

so if sender machine is slow at encrypting, receive on other end is slow, as it is limited by power of sender

i'm not sure otherwise

[anthonydenardo]

It looks like i can't start a new thread, i have a somewhat specific questions that i've had a tough time getting to work regarding open ssh. Could anyone point me in the direction of someone who may be able to troubleshoot me? Thanks guys glad to be here.