That is pretty frakkin' sweet.
Have you had any issues with the OS addressing that many USB devices? It looks like you've got a fairly good hub which probably presents itself as such to the OS, I've had some crappier hubs that start to complain when you multiplex >4 devices..
Thanks, and no the OS seems to handle it fine. The worst I've seen is that the bus is a bit bogged down, but that could probably be fixed by polling the FPGAs for nonces a little less often.
become fpga mining reallity?
tell us your experience with this type of mining please !
...and you spend a lot of money for your equipment...
Yes! This system is built using the boards that we (fpgamining.com) designed, produced, and are currently selling.
https://bitcointalk.org/index.php?topic=40058.0An honest review of this type of system should probably be written by someone other than me, since I'm far from impartial. Hopefully some of our customers will write about their experiences. I'll also try to write up some of the things I learned, so that others can learn from my mistakes.

The price is $580 per board at single quantity. There are bulk pricing discounts, though, which you can find in that thread.