well, its 1 thread per block, but grc just generates the flow graph
code, its technically out of the loop.
The unspoken text here is that Gnu Radio has two different scheduling
"policies" for a flow-graph--the default
for several years had been TPB (Thread-Per-Block). Which improves
your odds of "keeping up" with complex
flow-graphs across many blocks.
But individual blocks don't, as a rule, perform operations across
multiple threads. There are exceptions--the FFT blocks
now provide the *option* of doing their work across multiple threads.
But that's only worthwhile for very large
FFT operations--20K bins or so or larger. Computer science hasn't
yet come up with any general-purpose way of
converting serial algorithms into parallel ones that are
*unconditionally better* that their serial counterparts. So most of
the blocks in Gnu Radio are essentially serial in nature, with
occasional optimizations like the SIMD optimizations described
earlier.
Should have worded that more carefully. I can choose 8 or 16 bits over the
wire. My thinking was that I might be able to increase the rate of
decimation (on second thought, decimation has more to do with sampling
frequency than a data bottleneck) and also decrease the precision and use
an integer less than 8bits. Basically, I thought ethernet may have been
the bottleneck. Decreasing precision shouldn't be necessary, I'm just
trying to build an understanding here.
There's no support for anything other than 16-bit or 8-bit (I and Q)
samples on the wire. In some wide-band applications, like
radio astronomy, using fewer bits to gain bandwidth is pretty
commonplace. But in general-purpose SDR platforms, not so
much. But more importantly, handling 50Msps and *doing anything
useful* present significant challenges if you want to "do those things"
on a general-purpose compute platform.
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
