[mythtv] Hardware configuration

[Jesse Crews]

Nvidia MPEG support is for MPEG2
Disk looks fine.
VT8233 reportedly has problems, such as nonexistent PCI bus parking support.
This has been known to cause problems with certain sound cards and other PCI
devices, such as static, popping, etc.
Try looking for a "latency patch," manipulate the controls in the BIOS,
and/or uprgade your kernel.

I don't have such a motherboard, so I can't test any conjectures I have.
I can hypothesize, however, that your audiocard/anycard is interacting
poorly with the PCI bus. This in turn causes all kinds of things to go wrong
when other devices try to write to the bus, but the timing becomes fubar.

I can also state that the archives give the VT8233 a rather poor performance
grade, as do various windoZzzze users. It would be nice if we could just
swap out chips to gather data.

Also, check your system logs for any bad messages while you notice poor
behavior (I use telnet). You may also want to check for any unexpected
spikes in CPU loading.

----- Original Message -----
From: "Johann Klemmack" <klemmack@earthlink.net>
To: <mythtv-dev@snowman.net>
Sent: Monday, January 06, 2003 02:16
Subject: RE: [mythtv] Hardware configuration


> I have:
> Timing buffer-cache reads: 128 MB in 0.62 seconds = 208.06 MB/sec
> Timing buffered disk reads: 64 MB in 1.69 seconds = 37.97 MB/sec
>
> In Capabilities, I'm set to udma5, 16 of 16 r/w multiple sector transfers
> used, and look-ahead and write caching are enabled.
>
> I don't know what the north-south chipset capabilites are, but Abit lists
> chipset as VIA KT266A / VIA VT8233
>
>
http://www.abit.com.tw/abitweb/webjsp/english/mb_spec.jsp?pPRODUCT_TYPE=Moth
> erBoard&pMODEL_NAME=KR7A
>
> I know the NVidia Linux driver has MPEG decoding support, so I guess my
> hiccup is in harddrive/processor/bus (which is 266MHz).
>
> I have noted, though, that 640x480 MPEG4 compression will jerk a few times
> in the first minute, then settle out and only happen about once every 5
> minutes.  Not ideal, but it seems to me some buffer is overflowing or
> whatnot.  Still annoying.
>
> Any help would be greatly appreciated!
>
> Thanks,
> Johann
>
>
> > -----Original Message-----
> > From: mythtv-dev-admin@snowman.net
> > [mailto:mythtv-dev-admin@snowman.net]On Behalf Of Jesse Crews
> > Sent: Monday, January 06, 2003 1:33 AM
> > To: mythtv-dev@snowman.net
> > Subject: Re: [mythtv] Hardware configuration
> >
> >
> > What are your north and south bridges? What is the output of hdparm -tT
> > /dev/[your recording medium, i.e.: /dev/hda]?
> > Get a printout for hdparm -I /dev/hdx, and look under Capabilities. Make
> > sure r/w multiple is maxed out, and dma mode is correct, etc.
> > Commands/features should show that look-ahead and write caching
> > are enabled.
> > The best settings are typically the default.
> > ----- Original Message -----
> > From: "Johann Klemmack" <klemmack@earthlink.net>
> > To: <mythtv-dev@snowman.net>
> > Sent: Monday, January 06, 2003 00:20
> > Subject: RE: [mythtv] Hardware configuration
> >
> >
> > > Heh - weird.  I have an Athlon 1700+ and I can NOT get jitter-free
mpeg4
> > at
> > > 640x480.  I have a GeForce4 MX420 card, 512 RAM, off a VIA
> > chipset with an
> > > ATA100 harddrive, and WinTV.  Everything is running off of
> > Redhat 8.0 (b/c
> > > I'm a slacker).  I have DMA enabled for the harddrive access, but
trying
> > to
> > > run mpeg4 at all pretty much peaks out my processor.  I've thought
about
> > > just upgrading my proc to an Athlon 2100+ (don't worry, the
> > 1700+ will be
> > > put to good use ;-) but by the sounds of this, something's wrong in my
> > > system.  Any help on getting me jitter-free mpeg4?
> > >
> > > Johann
> > >