Re: [Discuss-gnuradio] Minimal Hardware to Run Gnuradio on?

[Tom Huppi]

On Thu, 16 Dec 2004, David Carr wrote:

> Tom Huppi wrote:
>
> >
> >>Even for really high rate USB transfers (40MB/sec) I see around
> >>10% utilization on a P4 2.4.
> >>
> >
> >That's good to know (and surprising to me!)  Do I understand
> >correctly that this is the load in processing, say, hdtv in the
> >form output by the USRP into an mpeg stream (or whatever)?
> >
> >I would expect that some types of processing are significanty more
> >CPU intensive than others.  Would you concur, and if so, can you
> >put a vauge, order-of-mag type estimate to the issue?
> >
> >
> This is the load resulting from transferring 40MB/s of data from a USB
> device to the GnuRadio framework (into ram essentially).
> Decoding a ATSC stream can only be done about 1/20th real time.

I see.  This is more along the line of my expectations.  I was
wondering if _that_ much was possible with the FPGA :)

I notice on the Wiki that the conjecture about the bandwidth of
the USB2 has changed to an assurtion (vis-a-vis hdtv.)  That was
neat to see, but it left me with a question (which I hate to spam
the Wiki with.)  Is it the case that the USB2 bandwidth is
sufficient for 1/1, but the overhead of related CPU-side
processing brings the ratio down?

Thanks for putting up with my questions,

 - Tom