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[Linrad] Re: Ubuntu 8.10

Roger beat me to it.

I recommend to anyone running near-real-time applications like Linrad, 
WSJT, WSPR, and MAP65 on a consumer O/S, including Linux: turn off the 
"eye candy" features offered by the O/S.  This applies to Ubuntu Linux 
and to any other O/S that offers snazzy "Windows-like" or "Mac-like" 
decorative features.  (I imagine that Vista is particularly bad, 
although I haven't used it.)

You can't afford to have your CPU paying close attention to on-screen 
"appearance features" (which of course offer no advantage whatsoever to 
your ham radio applications), when your program needs the CPU to be 
paying attention to signals you're trying to extract from the noise.

For what it's worth, I also advise users of ham radio software to make a 
decision about whether you are primarily interested in the radio 
applications, or the computer setup.  If the latter, then of course you 
may wish to install every new O/S release when it comes out; but then, 
do not be surprised if something in Linrad, MAP65, or whatever, does not 
work as you expect -- and do not expect the program authors to find time 
to solve your problem, right away.

I like to have stable O/S installations in both Windows and Linux that I 
can use both for program development and for operating.  I tend to stay 
with these installations, essentially unchanged, for at least several years.

Because it's relevant to discussions that have taken place on the WSJT 
developers reflector, I am copying this message to that forum, as well.

	-- 73, Joe, K1JT

Leif Asbrink wrote:
> Hi Roger,
> You have solved the problem:-) My Ubuntu 8.10 installation had
> 'Visual Effects' set to 'Normal'. That was the reason for
> abnormal behaviour.
> I have now set visual effects to 'None' and now the computer
> has normal behaviour and seems to run as well as with other
> distributions. (I have not analyzed timing issues in detail.)
> Thank you Roger:-)
>                         ---  0  ---
> According to public media here in Sweden it seems like the
> leading distributions are:
> 1)Ubuntu
> 2)Fedora
> 3)Opensuse
> 4)Mandriva 
> I am using Debian for my daily work, and I have now tested
> Ubuntu 8.10 and Mandriva 2009 (the most recent ones) Both of
> them (now) run well although I was not able to change the
> numbering of my soundcards under Mandriva. ALSA is different 
> there somehow.
> I will test Fedora and Opensuse also.
> Is there anyone on this list who prefers another distribution
> than the five mentioned? Slackware, Gentoo, CentOS or something 
> else? If you post a message to this list about why you prefer it
> I will install it on my multi-partition hard disk and try to 
> install Linrad on it to see if there are any surprises...
> 73
> Leif / SM5BSZ
> On Sun, 23 Nov 2008 09:43:03 -0500
> w3sz <w3sz@xxxxxxxxxxx> wrote:
>> What follows may or may not be germane to the issue you describe.
>> I found that an earlier version of Ubuntu [8.04] installed, by  
>> default, here with 'Appearance' extras selected that caused no problem  
>> on 'modern' Core2Duo machines but which brought to its knees an old  
>> Pentium III that I ran remotely via VNC and using the Gnome desktop.
>> The atrocious refresh and HID delays disappeared when I changed the  
>> 'appearance
>> enhancements' to 'none' by clicking on 'System' then 'Preferences'  
>> then 'Appearance' then "Visual Effects', and then clicking to select  
>> the 'None' radio button.
>> I found that neither 'Normal' or 'Extra' settings of the 'Visual  
>> Effects' gave satisfactory performance when the VNC server was active  
>> on this old, slow machine.  With the setting of 'None', everything  
>> works acceptably.
>> Check your 8.10 install and see if something other than 'None' is  
>> selected.  If so, select 'None', then recheck your CPU utilization.  I  
>> would also suggest rebooting and then checking it again after making  
>> the change from either 'Normal' or 'Extra' to 'None'.
>> Because you report that 8.04 did not exhibit porcine CPU behavior for  
>> you, this issue may not be related to your problem.  On the other  
>> hand, it is possible that the 'default' settings of 'Visual Effects'  
>> have not remained constant throughout the lifetime of 8.04, and that  
>> your default install settings for 8.04 were not identical to mine,  
>> thus preventing you from seeing the problem
>> with 8.04.
>> If the above issue is NOT germane to the problem you described, please  
>> accept my apologies for the bandwidth.
>> 73,
>> Roger Rehr
>> W3SZ
>> http://www.nitehawk.com/w3sz
>> Quoting Leif Asbrink <leif@xxxxxxxxxx>:
>>> Hi All,
>>> The latest version of Ubuntu is extremely CPU hungry when
>>> used with X11. Just running the system monitor loads the
>>> CPU with 20%. Xorg, the X11 server uses 15% and the system
>>> monitor uses 4%.
>>> Debian unstable which has the same system monitor uses
>>> 6% for Xorg and 4% for the system monitor.
>>> Debian stable uses the older system monitor which is far less
>>> CPU hungry. It moves the curves horizontally step-wize and
>>> uses 4% for Xorg and only 1% for the monitor itself.
>>> The above numbers are for a 2.6GHz Pentium IV.
>>> The very high load caused by the X11 server may make it necessary
>>> to increase the output delay margin and to decrease the max
>>> DMA rate.
>>> I would recommend Ubuntu 8.04 or any other Linux distribution
>>> if you want to run Linrad under X11.
>>> In case you love Ubuntu 8.10 for some reason, download
>>> svgalib1925-1.tbz from here:
>>> http://www.sm5bsz.com/linuxdsp/install/svgainst.htm
>>> The modified svgalib-1.9.25 package will compile under
>>> Ubuntu 8.10
>>> Press Ctrl Alt F1 to get into terminal mode and run Linrad
>>> from there (do not forget sudo.) Ubuntu 8.10 runs at full speed
>>> With svgalib in terminal mode:-)
>>> 73
>>> Leif / SM5BSZ

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