[mythtv] RedHat 8.0 and hardware questions.

Bruce Markey mythtv-dev@snowman.net
Mon, 16 Dec 2002 13:49:03 -0800


Richard Trice wrote:
> Current config.
> 
> Asus mb w/ 700mhz Athlon
> 256mb ram
> 13 gb / partition
> 2 west. dig 80gb drives, software raided (hdparam -t /dev/md0 gives
> 60MB/s writes)
> ATI tv wonder ve tuner
> Nvidia gefore 4 mx 64mb
> SB live!
> 
> Downloaded and installed version 0.7.  xawtv works fine (except the
> colors are a little washed out and the channels are off by 1).  I think
> I
> read a post about insmoding tuner type to 2.   I will try that.
> 
> My main question is, every time I try to watch live tv, it would crash
> on me and tell me I didn't have Xv support  nor the OSDdefault theme.
> I checked the themes dir and indeed it only had blue.   So is it because
> 
> my processor isn't fast enough to encode/decode (as per the docs?) or
> am I missing something else?
> 
> Also today, I was planning on running down and grabbing a new
> mb/processor/mem
> combo, and I wanted suggestions.  Got about $300 to spend.  I would like
> 
> this machine to be as quiet as possible.

Richard, good job of detailing your system and problems. I'll
try to match your effort in response.

1) As someone already pointed out, for Xv support you need the
nvidia Linux X driver from:

http://www.nvidia.com/view.asp?IO=linux_display_ia32_1.0-4191

2) CPU usage is dependent and how much encoding there is to
do which is most affected by the dimensions used for capture.
In settings.txt try:

int Width=352
int Height=480
# ...
str Codec=mpeg4

And leave the MPEG4 specific settings at their defaults.
On a 700MHz system I estimate this should use 70-80% cpu
time and should give you a decent picture. The file size
will be about 840MB per hour.

3) The significant piece of information from hdparm is to
verify that DMA is on with "hdparm -d /dev/md0". At the
highest suggested resolution for MythTV, the files are about
1.5GB/hour which is about 25MB/min or a little under a half
a megabyte per second. Therefore, speed doesn't matter, it's
the fact that DMA is turned on to prevent shuffling bits
around that matters.

4) Other people will have will have more useful opinions
than mine on CPU and motherboards. However, consider an AMD
Duron 1.3GHz. It's cheap, it runs much cooler than Athlons
and should be fast enough for a single tuner MythTV to
record at 640x480.

Hope this helps,

--  bjm