[hpsdr] laptop recommendations and linux observations

[John Melton]

Hi Erich,

I would not have thought that the USB bandwidth would be the problem:

The Ozy to PC USB bandwith at 192K is about 12312384 bps including I/Q
samples, microphone samples and packet header overheads.

The PC to Ozy USB bandwith will always be at 48K and is about 3120768
bps including output audio, tx I/Q samples and packet header overheads.

Total USB I/O bandwidth is 15.5 mbps.



Of more importance is the graphics interface.  I have found that
running on systems (laptops or desktop) the best performance with Ubuntu
is with an nVidia graphics card using the proprietary driver.  The
application is very graphics intensive and some of the open source
drivers do not perform that well.  However, having said that, one of my
desktop systems is an Intel i570 with built in GPU and that does appear
to perform well. It is dual core each with dual threads running at 3.3
GHz - or 4.2 GHz if I over clock it.

Have you tried running with the spectrum and the bandscope turned off to
see how it performs then.  That would give you an idea if the basic
system can handle the USB bandwidth and the DSP work.

Regards,

John g0orx/n6lyt



       
On Thu, 2010-10-28 at 17:25 -0700, Erich Heinzle wrote:
> ***** High Performance Software Defined Radio Discussion List *****
> 
> I will be getting a P4 2-3GHZ box with ~1GB of RAM in due course for little or no cost, but to allow mobile operation I am thinking about a laptop.
> 
> Can anyone on the list confirm if something along the lines of:
> 
> Compaq 620 XU333PA
> CPU: Intel Core Duo T4500
> RAM: 2GB DDR3
> HDD: 320GB SATA
> Graphic: Intel GMA 4500MHD
> Screen: 15.6” LED (1366 x 768)
> 
> would be ok for GHPSDR or PowerSDR
> 
> The screen res may be the only problem if the CPU would be OK.
> 
> 
> So far, I've figured out that:
> 
> a netbook 1.6GHz 1GB RAM is unable to run ghpsdr under ubuntu 9.1 and do anything useful
> 
> a desktop athlon ~2GHz a few years old now is unable to run ghpsdr under ubuntu 9.1, producing choppy meaningless audio, a fairly valid looking whole of HF spectrum, but can't generate a meaningful 192kHz wide spectrum for tuning.
> 
> although the Athlon managed with the SDR-1000 and powerSDR back in the day
> 
> Of note, and possibly of interest to HPSDR users generally:
> 
> OzyBulkRead read failed -1
> 
> errors seem to be due to slow USB ports.
> The Athlon motherboard USB port did not raise this eror, but the ports on the front of the Athlon tower did.
> The netbook ports did not raise this error.
> So, older PCs may struggle to handle the USB data rates.
> 
> 
> Thanks for any advice
> 
> Erich
> VK5HSE
> 
> 
>       
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