[Discuss-gnuradio] question on sample rate and ethernet rate

Hi all,

I am trying to figure out what I am doing/thinking wrong in the following example:

I have a simple flowgraph with a complex source sending samples to USRP.

The sample rate is fs=200e6/32=6.25 Msps which is the parameter that I set in the USRP.

I assume that this parameter will result in fs x 8 =  50 MBytes/sec transmission

over the ethernet (2 complex samples and float32 (4 bytes) each. This is the format that I have set in USRP).

However, when I observe the transmission rate on the system monitor (Ubuntu Linux) it reports a sustained rate of exactly half of it, ie, 25 MBytes/sec.

I cannot figure out what I am doing wrong and I get this factor of 2 mismatch.

All the above is run in an ubuntu box with gnuradio maint-3.7 installed and uhd 3.14.0

thanks in advance for any explanation,

Achilleas