> Certainly all that complexity can't be great for performance.
That's something worth testing, scientifically.
> It's the argument I make for fibre channel v. iscsi. It's true that iscsi hardware (being just standard networking stuff) is a lot cheaper and does the job 90-95% of the time. But in the edge case, especially w.r.t latency, fibre still wins, largely because it's simple in comparison.
One thing about this example that I would like to point out. FC implements much of the features of Ethernet and TCP/IP ... differently, so in that sense the complexity is at least comparable though probably not equal. As far as the implementation complexity I think that FC can get off easier because as a practical matter it is used in closed networks often with all components from the same vendor. Ethernet and TCP/IP have to deal with a lot more varied equipment and varied networks and have to be battle tested against _anything_ happening, all that extra implementation complexity has a real reason for being there.