[openib-general] IB: I don't like what I'm seeing.

Wed Mar 31 12:34:07 PST 2004

    ron> it's an old rule of networking that the only error
    ron> detection/correction that works is end-to-end. Because IB
    ron> puts that support in the card, it can not by definition do
    ron> end-to-end error detection/correction.

I guess I don't understand your requirements.  It seems like HPC apps
would not want to burn CPU checksumming all the data they transfer.
And even if you do checksum it once how do you know your memory
controller or cache controller doesn't corrupt it before the next time
the app uses it?

Certainly storage people seem to trust the reliability features in
SCSI over fibre channel.  I've never heard of anyone trying to run an
end-to-end reliability protocol between their disk and their
application.

In any case the UC transport of IB might work better for you.  However
the best network adapter for your application might be a multiport
gigabit ethernet NIC with all the checksum offload features turned
off.

 - Roland

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