Hello Tony,
According to my tests, it is only the capacity to do calculations which is the
key, as a lot of digital processng is done (for example for SDR or Panoramics).
I don't think RAM is important. I mean either you have sufficient memory or you
have not (and you will have a message error). But if you have enough, having
double or four more that the minimum does not change anything.
Note: with or without BPSK31 panoramic, I have about 2 % of CPU usage.
73
Patrick
----- Original Message -----
From: Tony
To: digitalradio@yahoogroups.com
Sent: Saturday, January 30, 2010 4:35 AM
Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band
Patrick,
Thanks for the information. As you may have read from my reply to Andy, my
CPU usage seems to be very low with Multipsk. It's well below 10%.
Is there a particular Multipsk mode or configuration that would tax the
system? I'd like to try it and see how it affects CPU usage.
Merci mon ami...
Tony -K2MO
----- Original Message -----
From: Patrick Lindecker
To: digitalradio@yahoogroups.com
Sent: Friday, January 29, 2010 4:51 PM
Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band
Hello Tony,
I have here two PC XP at about 2.4 GHz (single core):
I have compare these two XP computers on the same file to decode (in 110A):
* the first one (the oldest) which is an AMD Atlon 2500+ 1.09 GHz 768 Ko
RAM takes 75 seconds to decode it,
* the second one which is an AMD Atlon 2400+ 2 GHz 736 Ko RAM takes 20
seconds to decode it.
On the most modern (about 3 years old) with SdR and RS ID detection on 44
KHz, the CPU load is about 35 to 40 %, but on the old one it is 100 % (the
program does not work in fact).
So normally with a modern PC it is OK. With an "old" PC, it can be
problematic.
Note: with my Vista laptop (dual core), the CPU load is about 25 % in the
same conditions.
73
Patrick
----- Original Message -----
From: Tony
To: digitalradio@yahoogroups.com
Sent: Friday, January 29, 2010 8:36 PM
Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band
Andy,
I plan on switching to SDR in the near future. My current PC is a dual
CPU 2.2GHz Dell with 3 GHz RAM. Any idea what the minimum PC requirement is to
run Multipsk with SDR? Could you also tell us what processor you're running now?
Thanks,
Tony -K2MO
----- Original Message -----
From: Andy obrien
To: digitalradio
Sent: Friday, January 29, 2010 9:11 AM
Subject: [digitalradio] SDR-Radio with DM780 20M Digital Band
One of the things that I wanted to accomplish with an SDR receiver,
is the ability to keep an eye on the whole 14065 to 14115 frequency
range. If I was down on 14074 monitoring ALE 400 traffic, I would
miss Olivia signals that popped up in the 14109 area. I would also
miss Hell signals at 14068. Now the SDR affords the opportunity to
keep an eye all all at once. My venture in to SDR from a digital mode
perspective has led to a discovery that, other than Multipsk, the
current state of the art does not support direct monitoring of wider
I/Q data. I'm also challenged in that my PC cannot cope with the
Multipsk CPU demand when I try direct monitoring. So, at the moment I
am visually monitoring signals with the SDR and using traditional
software methods to decode the 3-4 kHz of audio that is fed from the
SDR to applications like DM780 or Fldigi.
At this screen shot http://www.obriensweb.com/sdrdm780.jpg
you will see how it appears. I am simply using DM780 and SDR-Radio
software together. When I need to transmit, I just use my TS2000
after dialing in the signal discovered by the SDR receiver. Simon
HB9DRV will likely "integrate" these two applications later in 2010.
I did catch a Russian on RTTY this morning that I would have otherwise
missed while I was slumming it in PSK31-land.. Multisk does RS-ID
over this entire 14065-14115 portion, and DM780 is likely going to
include this ability in the future. If people use RS-ID often enough,
it will be really "cool" to monitor 14065-14115 and get RS ID alerts.
So, just over a week playing around with the SDR receiver... I see the
potential... digital mode applications are not quite "there" yet.
When they are "there" (as in Multipsk) my PC isn't. This $41.00 Ebay
PC may eventually get retired for a slightly improved one with better
CPU. OK, back to keeping an eye on 14065-14115. A-ha, an SV3 calling
CQ RTTY, 14082.
Andy K3UK
