Re: Poor Data Rates with the USRP E312

[Philip Balister]

With the downloaded images for UHD-4.0 I saw a couple of things:

1) The CPU clock speed is set for speed grade 1 parts, not speed grade 3.
2) UHD-4.0 hangs after a while at higher data rates, I've also seen this
on a b200.

If there are fixes for these issues, you might get a bit more transfer
rate. Not sure it will get you the speed you need though.

Philip

On 11/22/20 9:20 PM, Joe Crossen wrote:
>  Hi all,
> 
> I'm attempting to use the USRP E312 as a wifi node using the gr-ieee802.11
> module...
> though for now I'm testing basic USRP functionality with a couple of simple
> GNU graphs.
> 
> Here's my setup:
> - the host is an Ubuntu 18.04 virtual machine with a bridged adaptor.
> Firewall disabled.
> - the USRP is the E312, connected via ethernet to the host network.
> - the host and USRP are both running GR3.8 and UHD4.0 (Zeus branch).
> - the host can see the USRP with uhd_usrp_probe.
> - the USRP is running the following GNU graph - UHD:USRP Source -> UDP Sink.
> - host is running the following GNU graph - UDP Source -> QT GUI Sink.
> - all block parameters are default.
> 
> I'm experiencing the following issues:
> 1. For sample rates > ~2Msps, the USRP spams overrun "O" and "D" characters
> (what does the "D" signify?) , regardless of whether the host graph is
> running or not.
> 2. At any sample rate the host graph spams the following message (when the
> USRP graph is running) - "gr::log :WARN: udp_source0 - Too much data;
> dropping packet."
> 
> And a question:
> 3. What sample rates are realistic for this setup, and what are the
> limitations? wifi channels span 20MHz, so I'm hoping to run at 20Msps
> 
> Thanks,
> Joe
>