[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Diagnosing the cause of D's

From: Marcus D. Leech
Subject: Re: [Discuss-gnuradio] Diagnosing the cause of D's
Date: Fri, 29 May 2015 14:23:46 -0400
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0

On 05/29/2015 02:13 PM, Marcus Müller wrote:
Hi Richard,

320kS is not the minimal rate; if I'm not mistaken it's 100MHz/512.

Ds are relatively serious, and I've rarely seen them: The typical "your system is too slow" results in "O"verflows; typically, you see "D" if UHD starts wondering where the sample packet n disappeared to, after receiving n-1 followed by n+1 (or so).

What's your ethernet hardware? (If on linux, "lspci | grep -i ether")
We've had some grief caused by USB3-to-ethernet-adapters which seemed to take delight in confusing at least UHD, its users and a significant part of its support team by randomly reordering packets on a direct link. Also, there's a single Intel Gigabit Ethernet controller that comes directly from hell, but it's becoming rarer in the wild every day.

Best regards,

The notorious Intel NIC is the 82579LM.   It drops packets, even at low load.  It's a FIFO control bug that they couldn't ever fix...

On 05/29/2015 06:07 PM, Richard Bell wrote:
Hi all,

I need some help determining the cause of D's being displayed from my N210 device. I know it means GNU Radio is not consuming the samples from my laptops Ethernet socket buffer fast enough, causing the USRP to overflow it.

What I would like to do now, is learn how to monitor performance such that I can figure out which part of my receiver is the bottleneck, so I can focus on optimizations there. I can't lower the sample rate anymore, because I'm already at the minimum rate the USRP requires (320k).

Would someone recommend a next course of action and tools I should download to proceed?


Discuss-gnuradio mailing list

Discuss-gnuradio mailing list

reply via email to

[Prev in Thread] Current Thread [Next in Thread]