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This page shows screen dumps of various operating systems running
Linrad on a 650 MHz Pentium III with a Delta 44 soundcard sampling
four audio channels at 96 kHz.
Figure 1 shows Windows 98 SE.
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Fig 1. Windows 98 SE sampling four audio channels at 96 kHz/24 bit. The processor load graph in figure 1 has three different regions. In the beginning the load is about 67%. This is when the computer is idle. The next region with 60% CPU load is when Linrad is running without any actions from the operator. The third region with a CPU load of 15% is with Linrad running exactly as before, but with the operator slowly moving the mouse in circles over the screen. Linrad can not evaluate CPU load under Windows 98 so system overhead can not be estimated from figure 1. Figure 2 shows Windows 2000. All parameters are identical to those used for figure 1. |
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Fig 2. Windows 2000 sampling four audio channels at 96 kHz/24 bit. The system monitor reports a total CPU load of 29% while Linrad reports 23.3%. The very low value (15%) reported by Windows 98 is probably not correct. Windows XP is shown in figure 3. (32 bit on a Pentium III of course.) It is similar to Windows 2000. Windows XP has sporadic disk activities that cause occasional loss of data with accompanying transcients that become well visible in the waterfall when the input is a single strong signal. |
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Fig 3. Windows XP sampling four audio channels at 96 kHz/24 bit. Windows Vista is shown in figure 4. It behaves quite differently from earlier Windows versions. The CPU overhead is large and some input data is lost as can be seen from the ugly transcients in the waterfall as well as from the somewhat too low sampling speed. |
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Fig 4. Windows Vista sampling four audio channels at 96 kHz/16 bit. The reason for the Vista problems is obvious from figure 5. It seems that the audiodg process holds the CPU for too long and that causes loss of data. |
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Fig 5. audiodg in Windows Vista while sampling four audio channels
at 96 kHz/16 bit.
(Screen parameters are slightly different from those used in all other screen
dumps on this page but that does not affect timing. Windows 7 has even more overhead than Windows Vista. Figures 6 and 7 show the system monitor information at a higher update rate compared to figures 4 and 5. |
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Fig 6. Windows 7 sampling four audio channels at 96 kHz/16 bit. |
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Fig 7. audiodg in Windows 7 while sampling four audio channels
at 96 kHz/16 bit.
The Pentium III is not fast enough for Windows 7. The effective sampling speed is too low by 170 Hz (0.2%) due to lost data. When running the Task Manager in parallel with Linrad the extra load from the task manager causes a dramatic increase in loss of input. The sampling speed becomes wrong by 17 kHz (18%) To SM 5 BSZ Main Page |