Thanks John,

I will definitely look into this.. I just did a record test on the server 
recording 20 MHz BW and I was only pulling 2% from the CPU so I think that is 
promising. But yes my goal is to record data at very high rates. Thank you!

By the way this thing looks amazing.. We will have to get one:
https://docs.wixstatic.com/ugd/07a03a_bf1ffbe54e0e4fd698485c8c0471a2e4.pdf

LJ Eads

From: John Ferguson [mailto:j...@deepwavedigital.com]
Sent: Wednesday, May 2, 2018 10:57 AM
To: Eads, LJ D. <lje...@mitre.org>
Cc: Derek Kozel <derek.ko...@ettus.com>; discuss-gnuradio@gnu.org
Subject: Re: [Discuss-gnuradio] How do I interface my X310 with an NVIDIA K80 
GPU in GNURadio

Hi LJ,

If you are trying to record data at very high rates, you GNURadio Companion may 
not be able to go as high as you want. Maybe your laptop has a fast SSD and 
your server has spinning disks? If you are wanting to test the limits of 
recording data with GNURadio to see if it works for your proprietary data rate, 
I would advise as follows:

1. Enable real-time scheduling and select "No GUI" in the Options block. See 
the transport notes on the E310 for how to get this to work by editing 
/etc/security/security.conf
2. Assign each block to a specific processor (Core Affinity) in the Advanced 
Tab and also increase the buffer size
3. Make sure you have a disk/array that can handle the rate you are trying to 
achieve.
4. You may need to adjust the dirty background radio in the kernel. you do that 
by editing /etc/sysctl.conf. This is tricky, so you should read up on how this 
works.

I've attached a shell script that you can use to modify add real time 
scheduling and adjust the kernel parameters. USE AT YOUR OWN RISK AS MODIFYING 
KERNEL PARAMETERS CAN BE TRICKY AND HURT YOUR SYSTEM.

As mentioned above, to test the bottleneck, try sending the data to a null 
sink. If it works there, then the issue is that your drive isn't fast enough 
can keep up.

You are correct that you are not using the GPU. GNU radio does not natively 
support GPU processing. We have had success wrapping pycuda into an OOT 
modules, and getting good performance. There are better ways, but that would be 
easiest to get started. Your GPU will require extra memory copies:

GNU Radio CPU > CUDA CPU > CUDA GPU > CUDA CPU > GNU Radio CPU

So depending on what kind of latency you can handle, this may or may not work 
for you. I'm assuming that the GPU question is not directly related to the 
recording question.

I hope that helped.

John



On Wed, May 2, 2018 at 10:32 AM, Eads, LJ D. 
<lje...@mitre.org<mailto:lje...@mitre.org>> wrote:
Derek,

Oops! The error was actually from just a simple WBFM Receiver block which has 
the audio sink. No soundcard involved in my setup.
I still don’t think I will be utilizing the GPU though because GNURadio isn’t 
showing up in the GPU processes.. Will I be at least utilizing the CPU? I will 
test the block diagrams I sent you on the server (I just have tested them on my 
laptop initially) and I will get back to you.

Thank you,

LJ Eads

From: Derek Kozel [mailto:derek.ko...@ettus.com<mailto:derek.ko...@ettus.com>]
Sent: Wednesday, May 2, 2018 10:20 AM
To: Eads, LJ D. <lje...@mitre.org<mailto:lje...@mitre.org>>
Cc: Müller, Marcus (CEL) <muel...@kit.edu<mailto:muel...@kit.edu>>; 
discuss-gnuradio@gnu.org<mailto:discuss-gnuradio@gnu.org>

Subject: Re: [Discuss-gnuradio] How do I interface my X310 with an NVIDIA K80 
GPU in GNURadio

Hi LJ,
I don't see an audio sink in either of those flowgraphs, are those the ones 
causing the error? Is there supposed to be a soundcard involved at any point in 
your setup? To just capture, record, and replay the file sink seems correct (to 
the limits of your hard drive write/read speeds).
Does sending and receiving to/from the USRP work if you use null sink and 
constant source to receive/produce data?
Derek

On Wed, May 2, 2018 at 3:08 PM, Eads, LJ D. 
<lje...@mitre.org<mailto:lje...@mitre.org>> wrote:
Derek and Marcus,

Thank you for the quick response! This is my first entry to the mailing list.

So I am trying to capture a very fast frequency hopping signal.. the rate is 
proprietary but probably one of the fastest rates on the market right now. I am 
currently just implementing a basic record/replay. I believe you are right that 
I am trying to route too much data to my speakers and that’s what I am trying 
to get out of.

I currently have had better success with the X310 right now using the GNURadio 
Live Environment on a USB and running Cat 5E from the X310 to my laptop.. now 
I’m trying to implement what I had on my laptop on this server that I setup. I 
attached the server specs.. currently using ubuntu 16.04.

Marcus.. I am confused as well! Because I feel like I should be using my CPUs 
and I am not.

LJ Eads

From: Derek Kozel [mailto:derek.ko...@ettus.com<mailto:derek.ko...@ettus.com>]
Sent: Wednesday, May 2, 2018 9:43 AM
To: Müller, Marcus (CEL) <muel...@kit.edu<mailto:muel...@kit.edu>>
Cc: discuss-gnuradio@gnu.org<mailto:discuss-gnuradio@gnu.org>; Eads, LJ D. 
<lje...@mitre.org<mailto:lje...@mitre.org>>
Subject: Re: [Discuss-gnuradio] How do I interface my X310 with an NVIDIA K80 
GPU in GNURadio

Hello LJ,
It would help to know what type of signal processing you are hoping to do and 
how you want to display or save the data. On generally available consumer 
hardware GNU Radio has been shown to be able to handle 800+MS/s of samples 
being displayed in spectrum plots.
It sounds like you are trying to route too much data to your speakers. Are you 
able to share your flowgraph? There is a screenshot function in the menu or the 
grc file could be attached.
Regards,
Derek


On Wed, May 2, 2018 at 2:28 PM, Müller, Marcus (CEL) 
<muel...@kit.edu<mailto:muel...@kit.edu>> wrote:
Hi LJ Eads,

I'm a bit confused: What has your sound card to do with GNU Radio, or
the USRP? And how is your sound card comparable to a GPU?

GNU Radio runs on CPUs.

Best regards,
Marcus

On Wed, 2018-05-02 at 13:23 +0000, Eads, LJ D. wrote:
> Hello,
> I just setup a USRP X310 that I plan on using with GNURadio over 10 gigabit.. 
> I have everything working and functioning properly (drivers and all) but my 
> only concern right now is that GNURadio is running off of the sound card on 
> my server and not the GPU. GNURadio isn’t able to handle practically anything 
> because I am limited by the sound card capability.
> How would I be able to use the CPU (Sixteen-Core Intel Xeon Processor E5-2683 
> v4 2.10GHz 40MB Cache (120W)) or the GPU (NVIDIA Tesla K80 GPU Computing 
> Accelerator - 24GB GDDR5 - Passive Cooler) for better functionality of the 
> X310?
>
> My current error: “gr::log : INFO: audio_alsa_sink0 – [default]: unable to 
> support sample rate 500000
> Card requested 192000 instead”
> https://lists.gnu.org/archive/html/discuss-gnuradio/2014-06/msg00418.html - 
> This sounds like my issue
>
> Thank you,
> LJ Eads
>
>
> L J Eads
> The MITRE Corporation
> (937) 874-7240 (Office)
> (954) 554-6801 (Mobile)
> lje...@mitre.org<mailto:lje...@mitre.org> (FFRDC)
>
> _______________________________________________
> Discuss-gnuradio mailing list
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