David Diggles <da...@elven.com.au> wrote: > I am looking for ways to speed up scp over 10GigE. > With parallel transfer of 4x 8GB files, I get > the following test results with various ciphers. > > These tests maxed out 4 cores with encryption overhead.
Assuming that crypto actually is your bottleneck, here are a few hints: First, use a faster MAC: -m umac...@openssh.com > SSH Options: [-o Cipher=arcfour] > SSH Options: [-o Cipher=blowfish] These only apply to the SSH1 protocol and are ignored otherwise. > SSH Options: [-o Ciphers=arcfour] > SSH Options: [-o Ciphers=blowfish-cbc] > SSH Options: [-o Ciphers=aes256-ctr] > SSH Options: [-o Ciphers=3des-cbc] There are really three interesting ciphers: aes128-ctr, aes128-cbc, and arcfour128. aes128-ctr is the default and already plenty fast. aes128-cbc used to be the default until a security problem with the way CBC mode is used in the SSH2 protocol was discovered. In principle it isn't any faster than aes128-ctr, but in practice it may be since it uses OpenSSL's optimized EVP_aes_128_cbc() function while aes128-ctr relies on calls to the low-level AES_encrypt() primitive. arcfour128 is the fastest cipher supported. (Plain "arcfour" may be a tad faster, but has known security problems.) -- Christian "naddy" Weisgerber na...@mips.inka.de
