GRC samp_rate question

Hi List,

I am working on an energy detector on USRP1 and i use GRC to develop a
model first.
I need to scan some start and stop freqs. and determine if energy
level is exceeded.
As i search on the net, the bandwidth of the USB interface is 32MB and
16MB is used for I-Q samples respectively.

If i set the samp_rate parameter = 8M on GRC, does that mean, i
receive the whole 8MHz BW for a given center freq.(from fc-4M to