Re: [Discuss-gnuradio] Intel Atom is NICE.

[Marcus D. Leech]

Bob McGwier wrote:
> One does NOT need to spend thousands of dollars on an SDR computer for most 
> operations.   That is a convenient excuse for me to justify my computer 
> budget for "development" and get high end things to play with (so I can kill 
> aliens from another galaxy or FSU laboratory with impressive graphics in my 
> "spare time").  But most people need to really justify the need for the high 
> end computer in my mind and they cannot.  That is my point in all of this.
>
> SDR wants to be on consumer/commodity level processors and SoC to be in 
> everyone's "coffee budget" and taken for granted in the ideal world in my 
> book.  There seems to be little gained by optimizing this for Quad core 
> extreme processors with massive GPU's sitting on them,  tons of expensive 
> high speed memory, and the world's fastest drives and costing well upwards of 
> $1000 US.  Lightweight,  easy to distribute, with browser level GUI's and 
> distributed everything on inexpensive processors and we rule the world.  You 
> can call me Dr. No. and SDR Working group chairman stands for SPECTRE DUMB 
> RESEARCH working group. 
>
>   
While I can heartily agree that for the expansion of SDR into the
consumer space, you want it to run on low-power processors, etc, I can't
  agree that "for most operations" you don't need a high-end CPU.

For example, 802.11 at anywhere approaching 802.11b bitrates needs some
serious iron, and yet in our world (the world of SDR
  geeks), wanting to build SDR/GnuRadio-based 802.11b implementations
seems a fairly common goal.

In my work in radio astronomy, I've found that despite the relative
simplicity of the basic functions my software provides--full-bandwidth
  spectral display, and total power, for one or two channels, big iron
is necessary.   I recently upgraded to a quad-core Q6600 to replace
  a dual-core Pentium D 940.  The quad core loses against the dual-core
because of a difference in maximum clock speed.  I can
  run the D 940 at 3.2Ghz forever, and it can process a full 8Mhz of
dual-channel, complex bandwidth.  The Q6600, on the other hand,
  is unstable above 2.85Ghz or so, and can't sustain more than about
5.3Mhz of dual-complex-channel bandwidth without incurring
  massive USRP overruns.

Despite the wonderful new multi-threaded Gnu Radio framework, it seems
that at least one of those threads really needs as many
  MIPs as the processor can throw at it, because it has to keep up with
a real-time data source.

Any time you're dealing with having to suck in (or send out) as much
bandwidth as the USRP can tolerate, and
  *actually doing something* with the entire bandwidth, you need
ManyMIPS(tm).
  Which means spending $$$ (although, my dual/quad-core system was much
less than the $1000.00 you quote above).

-- 
Marcus Leech
Principal Investigator, Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org