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