[Discuss-gnuradio] USRP2 dropping data

[David Evans]

Hi,

setup...
-2x USRP2s + GPS 10MHz reference + 1PPS
-Single GigE port, with USRPs on GigE switch
-Zotac H55-itx MB + i3 processor, so quite high end.
-VRT branch code. I also use PPS via DCD line to trigger when to load time on 
next PPS, enable real time scheduling, ref to SMA, pps to SMA, 
config_mimo(MC_WE_LOCK_TO_SMA) and use similar code to rx_streaming_samples 
(but 2x USRPs).
-decimation set to 10
-feeding in same off tune carrier into RFX400s to get a sine wave, just to 
observe sync.
And yet, after sampling 30 seconds of data to file from both USRPs and the code 
reports 0 underruns, 0 lost packets, no S's,  I often get dropouts/missed 
packets.
As I am receiving only, I gather from various posts that a single eth port + 
switch should be Ok. The data captured always starts off in sync, it just goes 
wrong sometime during the capture. The number of bytes captured is normally the 
same for both channels too.

Hope you can help please,