I too have heard these arguments. When I heard them I felt a sense of deja
vu -- anyone remember
when the conventional wisdom was that "voice will never run over IP?" In
fact, most of the
assertions below are fallacies or soon will become fallacies. The only real
about the exact form the technology will take -- NAS vs. SAN, etc.
a. TCP is too CPU intensive and creates too much latency for storage I/O
There are now task specific processors and co-processors that can handle 1
rate today, and will run at 10 Gbps line rate in 18-24 months. So this
already fallen by the wayside.
b. The IP stack is too top heavy and processing packet headers is too
slow to support storage I/O operations.
Too slow? If that were true, we wouldn't be able to handle OC-192, would we?
The real question is
how much the chips, switch fabric and specialized memory will cost, and how
competitive this will
be with existing technologies such as Fibre Channel, both for short and long
c. The maximum throughput of a GE TCP/IP connection is 768 Mps, which is
too slow to support storage I/O operations.
That figure was achieved with minimal hardware acceleration. Pushing it by
an order of magnitude within 24 months
is not unimaginable. If you were willing to throw more hardware at the
problem, it might be possible to handle
a 1 Gbps bit rate on 8 lambdas at the same time *today*. How does 8 Gbps of
throughput today sound, with 80 Gbps
in 18-24 months?
Is any of this true?