keychain vs ssh-ident [closed]

Please look at this answer over on the Unix Stack Exchange site: https://unix.stackexchange.com/a/90869

ssh-key with passphrase, with ssh-ident

ssh-ident is an utility that can manage ssh-agent on your behalf and load identities as necessary. It adds keys only once as they are needed, regardless of how many terminals, SSH or login sessions that require access to an SSH agent.

ssh-key with passphrase, with keychain

keychain is a small utility which manages ssh-agent on your behalf and allows the SSH agent to remain running when the login session ends. On subsequent logins, keychain will connect to the existing SSH agent instance.