I prpose a system that utilizes the burgeoning market of low cost USB Flash Drives in a simple RAID array to provide hughe throughput with zero latency - only raw tthroughput would be meaningful.

Each subcontroller would be a simple embedded CPU (e.g., an ARM920) with some ROM and RAM (only a tiny amount of both is needed, the design will be cacheless). To the CPU would be sixteen independant USB2.0 master ports - each capable of 480Mbits/s. This would only need to be a partial USB2.0 implement as each master only supports one device and only one type of device, a memory stick.

All sixteen need to be the same, and it provides RAID6 across them (so only fourteen provide data). With 4GB sticks, that would provide 56GB of data per module. Each module could provide about 280 to 420MB/s bandwidth with near-zero overhead.

Modules would be interconnected with either a simple paralell bus, and about 6 could be placed inside a 1U rackmount case with redundant powersupplies, fans, etc. Or alternatively, each module could convert the data to SATA-II and then use a more standard host board.

This would aggregate to 1.6 to 2.5GB/s which could saturate a 10GbE uplink!

There would then be a seventh board connected on the bus that is the host controller with 4 SFP/GbE ports for connection to the network, as well as a 10/100bTX port for management. Depending on the implementation of the module boards, this could simply be a SATA-II RAID controller (so you could even RAID5 the modules themselves which are also RAID6 - though for speed RAID0 would be better).

Now, with current prices for flash at about $80/GB (retail, bulk could be cheaper, don't know), a stuffed unit with 4GB modules would cost $30K for just the memory (and probably about $4K for the subsystem), placing it rather high on the SAN $/GB level. However, on the $/IO it would beat every harddrive solution there is.