How to setup two USRPs B210 in GNU Radio

Question

I am trying to setup two USRP B210 with external Octoclock in GNU Radio in order to achieve 4 RX channels.

What is the right way?

1.One USRP source with Num Mboards = 2, and Num Channels = 4.

or

2.Two USRP source, each with Num Mbords = 1, and Num Channels = 2.

Answer 1

1.One USRP source with Num Mboards = 2, and Num Channels = 4.

Probably can't do that, UHD's multi_usrp doesn't deal with multiple b2xx devices, so only your other option

2.Two USRP source, each with Num Mbords = 1, and Num Channels = 2.

works.