I do have a similar, but lower-performance thing as a backup device (it only does 900K/s over 100Mbit Ethernet, but this is rsync+ssh, and I suspect SSH is CPU-bound, especially as the only ARM cross-compiler I could get working was the old car-player one) -- but the x86 server in question is also a firewall and Freeview DVR, all of which I suppose I could hang off a hacked NAS as USB, but that's a lot of hassle.

Peter