NooElec NESDR SMArt Successful PPA Install v2.6

[Joseph Nieves]

Laptop: Dell Inspiron 11z 1121, 8GB memory

OS: Ubuntu 16.04.1 LTS (xenial)

Kernel: 4.4.0-59-generic

lsusb: Bus 002 Device 007: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T

Dongle: NooElec NESDR SMArt

http://www.nooelec.com/store/nesdr-smart.html

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Thanks for making the install process pain free.  Some observations:

Upon first launch, there were no errors, yet 'Start/Stop' gave no indication the RTL dongle was being recognized.  It was plugged in prior to beginning the install process.  Tried poking around and tweaking a few things.  From what I recall, I must have gone through 3-4 'Start/Stop' cycles before GQRX eventually crashed.  After rebooting my Ubuntu system, I launched GQRX and it worked as expected.

While running 'volk_profile', I did notice the tests were quite exhaustive.  It took a lot longer to run than expected.  I ran it while other applications were running in the background.  Would it be best to launch solo?  Can 'volk_profile' be run more than once?

73 de N2TEE, Joe

[Robin Gape]

Joe,

1) volk_profile is an obsessive tweaker, which tries many ways to perform and time a number of number-crunching operations, with the idea that the quickest method for some particular operation is selected in a profile.

2) for good results, as little as possible should be running in the background whilst volk_profile is running.

3) although the man page is disappointingly succinct, it makes it clear—or tries to!—that volk_profile may be run as many times as one wishes, and the configuration file is rewritten at the end of each full run.

4) volk_profile runs single threaded. Completion will take anywhere from 5 minutes (or less) on an Intel i7 to half-an-hour on an Atom powered machine.

5) If the Intel thermal daemon is in use—installed by default on Ubuntu 16.04 and later if an Intel CPU is detected—then one core will be overclocked for the duration of the test until the temperature becomes excessive. With an AMD processor then the performance governor will most likely be in use, and one core will be set to maximum. If the processor is an ARM device, again one core will be maxed out, but the mechanisms will be different.

HTH, 73,

Robin, G8DQX

[Alexandru Csete]

Hi Joe,

Thanks for the info - I'm glad that you got it working using the PPA.

Regarding the reboot, it would have been sufficient to unplug and
reinsert the device. The PPA also installs the driver and it is not
unusual that a hardware reset is necessary before the newly installed
driver can detect the hardware. The driver package contains scripts to
do that, but these do not always work, so it is safest to plug in the
device after the software has been installed.

73
Alex OZ9AEC

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[Joe N2TEE]

On Thursday, January 19, 2017 at 2:33:58 PM UTC-5, Robin, G8DQX wrote:

<snip>

3) although the man page is disappointingly succinct, it makes it clear—or tries to!—that volk_profile may be run as many times as one wishes, and the configuration file is rewritten at the end of each full run.

Thanks for the clarification.  I'll try it again upon a fresh restart with no apps launched.

 

4) volk_profile runs single threaded. Completion will take anywhere from 5 minutes (or less) on an Intel i7 to half-an-hour on an Atom powered machine.

My own fault for not doing a bit more research on its behavior.  Had it running in the background while checking email via Chrome which is a bit of a memory hog.  Was surprised to see 'volk_profile' still running.  At first glance, I though it had gone into some sort never ending recursive loop.  Scrolling through terminal showed each test to be unique.  On my little i3 laptop, I estimate about 15 minutes or so to complete.  Just the sort of thing which happens when you want to shut down for the evening.

  

<snip> 

[Dave Baxter]

Hmpf...

On this Dell XPS i7 driven box (running Mint 17.2 32 bit) it took over 30 minutes!   And yes, that was with not a lot else going on.  The CPU fan got a good workout as a result.

On Thursday, 19 January 2017 19:33:58 UTC, Robin, G8DQX wrote:

4) volk_profile runs single threaded. Completion will take anywhere from 5 minutes (or less) on an Intel i7 to half-an-hour on an Atom powered machine.

73.
   Dave G0WBX.

[Derek Hanson]

Here's a question. I ran the volk_profile utility and was able to view the report in text edit but how do I implement the optimizations? Thanks

[Alexandru Csete]

On Fri, Jan 20, 2017 at 10:46 PM, Derek Hanson <derek....@gmail.com> wrote:
> Here's a question. I ran the volk_profile utility and was able to view the
> report in text edit but how do I implement the optimizations? Thanks

Hi Derek,

Not sure what you mean with implement optimizations... The volk
library already implements a lot of optimizations, it just has to find
out which ones are best suited for a given CPU. That's what it checks
using the volk_profile tool, which saves the results in
~/.volk/volk_config
GNU Radio will then use this configuration at runtime.

So, there is nothing to do besides running volk_profile.
Does this answer your question?

Alex