[Skimmertalk] CW Skimmer - more

[Pete Smith]

I used Process Explorer from that site.  I can always try another, I guess.

73, Pete

At 05:54 PM 11/11/2008, you wrote:
>Pete
>
>Have you tried use another process monitor such as the MS System Internals 
>process monitor to compare use to compare Skimmer and Task Manager 
>measures? It might give you some clues. You can download Process Monitor 
>2.0 found under Process utilities from here
>
>http://technet.microsoft.com/en-us/sysinternals/default.aspx
>
>
>... Syl
>
>Sylvan Katz, VE5ZX
>Saskatoon, SK
>
>
>
>--------------------------------------------------
>From: "Pete Smith" <n4zr at contesting.com>
>Sent: Tuesday, November 11, 2008 4:33 PM
>To: <skimmertalk at contesting.com>; <SDR-IQ at yahoogroups.com>; 
><dxatlas_group at yahoogroups.com>
>Subject: [Skimmertalk] CW Skimmer - more
>
>>Now that I've proved (to myself at least) that I'm not completely nuts, let
>>me prevail on your patience with a slightly more complicated question.
>>
>>Under normal circumstances, I understand that CW Skimmer's own CPU usage
>>indicator will normally show a somewhat higher number than Task Manager's,
>>because it is looking at peaks from one application while Task Manager
>>looks at an average over a second of so of all the processes that are 
>>going on.
>>
>>That being said, I find that there is a pretty logical and explicable
>>relationship among the Skimmer CPU number, the bandwidth set on the Radio
>>tab, the number of decoders, and the number of candidate data streams (the
>>last two are the "98 of 456 decoders" numbers).
>>
>>Incidentally, it's little-known, but the Sample Rate choice on the Radio
>>tab *does* affect both the bandwidth covered by an SDR-IQ when used with
>>Skimmer and (therefore) the CPU demand.  To verify this, bring up Skimmer
>>and change from 48 to 96 KHz.  You'll see the CPU loading go 'way up.
>>
>>Finally, here's the question.  Have you ever noticed a situation in which
>>the CPU utilization of the total of the two Skimmer processes) as reported
>>by Task Manager is much higher than the CPU utilization being reported by
>>Skimmer?  I see this all the time, but have not been able to figure out
>>what causes it, or what makes it go away.  All I know for sure is that
>>sometimes something is happening to impose a much higher load on the CPU
>>for a given number of decoders than is the case at other times.  Sometimes
>>I'll see this as much higher CPU utilization in 48 KHz mode than in 96 KHz
>>mode.  Sometimes I can cause things to revert to normal by changing Sample
>>rates, stopping and restarting the waterfall, or restarting the program.
>>
>>One good question that Alex asked was whether it might be a mistake by the
>>Task Manager.  All I can say is that I don't think so, because there is a
>>definite slowing of other programs when Task Manager says utilization is
>>over 85 percent, even though Skimmer itself says it is only using 50-55
>>percent.  Moreover, I see the same phenomenon in Process Explorer, which is
>>a completely separate program - I can't be sure that it doesn't measure CPU
>>utilization the same way, of course, but it seems to be a stretch, because
>>Process Explorer was not developed by Microsoft.
>>
>>Anyway that's the question - if you could, just keep your eyes peeled, or
>>run some tests, whatever you have time for.
>>
>>Thanks and
>>
>>73, Pete N4ZR
>>the World Contest Station Database is back...
>>www.conteststations.com
>>
>>
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