(DES-CBC)**3 Throughput (was Re: DES wonk's delite)

For those who want throughput in known units (rather than the weird ones
I used in the previous message, for comparison purposes only) ..

> Assume it takes x nsec to get on and off chip (either pure DES, EDE2 or XOR),
> y nsec to do the single DES, z nsec to do EDE2 and w nsec to do XOR and v nsec
> to do DES-CBC on-chip.
>
> Scheme         Total Latency           Throughput
EDE#-CBC        2x+z+w                  8/(2x+z+w)  GB/sec
(DES**3)-CBC    4x+3y+w                 8/(4x+3y+w) GB/sec
(DES-CBC)**3    3x+3v                   8/(x+v)     GB/sec

I would also assume that to a first approximation:

        z = 3y
        v = y+w
        w << y

 - Carl