>doesn't it look like the USB 2.0 is a heavily constraining bottleneck?
>
>
Yes, USB2.0 is the bottleneck.
>And, if I'm not wrong about this, will it be possible in the future to
>have a USRP <--> PC interface which doesn't limit us so much.
>
>
Other than 802.11, there aren't many applications that require more than
8 MHz of bandwidth.
We're building cards for channel sounding and other wireless applications that typically require sampling of bandwidths greater than 8 MHz. For this we're using a PLX chip -- 9054 (32-bit/33 MHz). With this chip we're expecting to achieve a throughput of about 90 MByte/second. You can try the 9056 if this doesn't meet your bandwidth requirements.
Cheers.
Nikhil