Re: [Discuss-gnuradio] A question on gnuradio capacity of handling real time data streaming and signal processing with USRP N210 + gnuradio on host linux computer

[Tom Rondeau]

On Tue, May 14, 2013 at 12:45 AM, Marcus D. Leech <address@hidden> wrote:
> Dear Group,
>
>
>
> I have a need to do real time or near real time tracking (most likely
> phase-lock loop) of multiple narrow-band carriers/tones in a 1MHz band of
> signal input using USRP N210 and gnuradio running on a reasonable linux
> host. Say the carriers/tones are embedded in the band from -500 kHz to +500
> kHz. If I want to lock on to 20 carriers in that band using gnuradio PLLs,
> will this choke up the computer? If there is a problem, I also would like to
> think how to reduce data rates. But I don’t know whether multiple LO’s are
> an option.
>
>
>
> Thanks for reading,
>
>
>
> LD
>
> The best thing to do is to put together a simulation, and see if your
> computer is up to the task or not.
>
> Something that we don't have a really good handle on in Gnu Radio is some
> estimates for the computational complexity of
>   individual blocks in a flow graph.
>
> If we did, one could do some simple arithmetic:
>
> add up all the complexities of all the blocks on your "fast path" (by this I
> mean blocks that must necessarily operate at the input sample rate)
> multiply that by the sample rate
>
> That gives you an idea of the numbers of MFLOPS/GFLOPS required to support
> your application.
>
>
> --
> Marcus Leech
> Principal Investigator
> Shirleys Bay Radio Astronomy Consortium
> http://www.sbrac.org

We actually now have the Performance Counters. They have just been
added and are undocumented, almost completely. We're still working on
them as a concept, but we'll be promoting their use more and more soon
(once 3.7 is done, most likely). But they can tell you the
instantaneous, average, and variance of the amount of CPU time spent
in work for all blocks. You can get these values by calling
pc_work_time() (add _avg() or _var() for the other two statistics.

There will be more stuff on this in the coming months.

Tom