[mythtv-users] Re: New user questions

Matthew Wolenetz wolenetz.ma at comcast.net
Sat Feb 7 09:36:30 EST 2004

I'm using a dual Celeron 466MHz box (yes, with an ABIT MB that yields 
APIC errors
even when booted with "noapic") and get smooth simultaneous capture and 
playback of 720x480
4500/6000Kbps PVR-350-captured, Matrox MGA400 1280x1024 displayed video.
If I turn on the PVR-350 decoding, mythtv's backend "disappeared" 
frequently (2 or more times in
a day, apparently depending on system load, especially with 0.13).  With 
PVR-350 decoding
(and simultaneous capture), I have just about 1 full unloaded CPU, but 
you must factor in I/O when
trying to do even more.  I've had the system smoothly capturing and 
replaying MPEG2 described
above at the same time as encoding MP3's with MythMusic.  With PVR-350 
decoding turned off
for greater stability, capture and playback takes a little over a whole 
"CPU", with no apparent frame
loss unless I do something like un-niced MP3 encoding or lots of other 
disk I/O.  Simultaneous
commercial flagging does not cause frame loss, although just the "blank 
screen" detection takes
slightly longer to run than it did to capture.

The box is a good space heater and mythtv front/back combo :)

Overclocking this motherboard is definitely not recommended from what 
I've seen online.  Putting
a heatsink/fan combo on the motherboard's chipset appears to have solved 
infrequent (once a week)
hangs (usually while running xscreensaver...)

>>>The only remaining problem is the load average shoots up to 3 or 4 when I'm
>>>watching live tv at 160x160 (the lowest available resolution).  But 'top'
>>>says the CPU is around 30-35% idle.  Where is the load coming from?  Disk
>>>activity?  Interrupts?
>>I tried increasing the resolution on the theory that the CPU was actually
>>unused and the load average was caused by disk activity.  I can get 256x192
>>resolution with about the same performance.  The quality isn't great but it
>>is pretty watchable.  320x240 is out of reach, it pegs the CPU and drops a
>>couple of frames every few seconds.
>>Is anyone using a P3 or Celeron running about 500MHz with a hardware MPEG
>>encoder and software decoding?  If so, what kind of performance/resolution
>>does it have?
>I'm using a PIII 450 and a Hauppauge PVR 250 card.  Using the default
>resolution from the AT RPMs and X set to 800x600 I get smooth video
>playback.  There was a bit of jerkiness during the first few seconds of
>playback, but changing the hdparm settings took care of that.
>I'm not exactly sure which settings determine exactly the resolution that
>is being used (one of these days I'll read the manual)... but it looks
>great with the default settings.
>>"Perhaps the most widespread illusion is that if we were in power we would
>>behave very differently from those who now hold it -- when, in truth, in
>>order to get power we would have to become very much like them."

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