Hi Paul
Useful ... but I took a look at the areas you mentioned below and
there does not seem to be anything wrong as far as I can tell...I am
very impressed with the depth of what you know..
My system is keeping perfect time as of the last 24 hours.
So here is one more tidbit...
the sound from the line out is fine ... it feeds my AIW 8600DV... but
the speakers still have what is more correctly called looping.
So, there are two possible answers as far as I can tell.
1. Could it be that my speakers have gone bad ...Evo Sonic XS 2.1's
... I doubt it... but I will test some new ones in the morning.
or
2. It is the motherboard...
Since the line out is fine ... it could very well be the speaker. They
have not bin abused but I will test this before I order an new
motherboard
Thanks Again
David
That is a useful observation.
When the operating system is not running, there is a clock in the Southbridge
that keeps time. There is a 32768 hertz crystal next to the Southbridge, and
the circuit in the Southbridge is very similar to that of a digital watch.
When the OS is running, the value stored in the RTC in the Southbridge, is
transferred to system memory. From that point onwards, clock tick interrupts
signal to the processor, when to increment the location in memory that
represents the clock. So the time keeping is based on clock tick interrupts,
rather than the RTC, for as long as the OS is running.
If the time is drifting in that case, one reason can be that the clock tick
interrupt is not getting serviced in time, so opportunities to increment
the clock are being lost. The clock tick interrupt has a high priority, so
it should be difficult to lose them. (That is precisely why it has a
high priority in the first place, to reduce the chance of losing them.)
Now, consider if you have some kind of interrupt problem. The sound system
also relies on interrupts for service. The sound chip requires rather prompt
service, and if service is not received, funny things happen.
To give an example of what the sound does, when starved, consider when a
game crashes the OS. I used to have a problem with a system while playing
Quake, and the sound would play in a loop, using the same fraction of a
second worth of sound samples. That wasn't an "echo" as such, because the
amplitude of the sound didn't decrease with time. It was more of a "looping"
of the sound. If the software could somehow recover, and feed fresh buffers
of data to the sound chip, then new sounds would come from the chip.
Part of the fun with sound problems, is terminology. Finding descriptive
terms that mean the same thing to everyone reading the posts. To me,
echo implies reverberation, like sound in a cave or yelling in a
mountain range. In that case, there is an echo, and with each return
trip, the amplitude of the echo is reduced until it dies out. "Looping"
is where the same buffer of sound data, is played over and over again,
because the sound chip has no fresh content in the queue - in that case,
the amplitude remains the same for each replay of the data in the buffer.
This probably isn't going to be enough to figure out the problem, but
anyway -
Control Panels:Administrative Tools
erformance has the capability to
display a limited set of metrics. If you right click in the display pane,
and select "Add Counters", then in the Add Counters dialog, you select
a Performance Object of "Processor", then select "Interrupts/sec", that
will give you a trace on the screen. If I do that on my Win2K system,
I see a more or less flat line (as long as the mouse doesn't move), and
the level of interrupts seen is:
2090 interrupts/sec (alt-tabbed out of a 3D game, so it is in the background)
(The video card is still "running", even when the game is not
(Extra interrupts are from the video card))
130 interrupts/sec (no game in background, mouse not moving)
Check your system, to see what kind of level it is running. If there
are thousands of interrupts per second, when no programs are
running, and the mouse if not moving, it could be you have a
spurious interrupt problem. The problem there, is I don't see
a chip on the NF325, I recognize as a trouble-maker. It could
simply be a defect of that particular board, I suppose (a good
chip gone bad).
If I wanted to further illuminate the issue, at this point I
might switch to a Linux LiveCD, and see if I could get a
record of interrupts versus IRQ number. I don't see the ability
to do that, in Windows. But perhaps Linux has a means to do that.
Also, take a look in the Event Viewer in Windows, and see if there
are any strange error messages in there. Maybe if there is an
interrupt problem, some side effects would be present in
Event Viewer.
Paul
