[mythtv-users] Fast CPU, DMA enabled on HD, Xv enabled, still getting pauses in Live TV

Tue Aug 19 09:56:52 EDT 2003

It is not the CPU. I have great performance with an athlon XP 2000. And 
I use fairly demanding encoding settings. I also have used a single 
drive with good results, though now I have two. I don't think there is 
anything in your specs that need upgrading, but I suspect you have 
broken hardware or hardware conflicts, or broken software. It is not 
that you need to upgrade your specs.

good luck

Cedar

On Tuesday, August 19, 2003, at 12:44  AM, Joe V wrote:

> Okay, now I'm starting to go nuts.  I've gone through
> the mailing-list archive, and have tried all sorts of
> things.  Changing DMA parameters, recompiling MythTV
> with -march=xthlon-xp, trying "nice" on mythbackend,
> and several other things.  And I'm still getting
> skips, and with this hardware, I don't see how I could
> be having problems.  All I want to do is run
> mythbackend and mythfrontend on the same PC without
> stuttering in the video/audio.
>
> Perhaps based on my hardware/software setup, somebody
> can make some additional recommendations.
>
> Hardware:
> - Albatron KX400-8X motherboard (brought the ECS board
> back to Fry's, too many problems) - VIA KT400 chipset
> - Athlon XP 2400+ CPU (2GHz real speed, 266MHz FSB)
> - 512MB RAM (DDR333) - the BIOS indicates that the RAM
> is running at 133MHz * 2.5 (333MHz)
> - Matrox G400 Dual-Head (hooked up to a monitor, so
> using Xv)
> - Western Digital Hard Drive UDMA 100
> - Soundblaster Live! 5.1 (using in full-duplex mode
> with kernel drivers)
> - Leadtek Winfast TV 2000 XP (I put in gbuffers=8)
> - Tulip clone Ethernet card (no onboard NIC)
>
> Software:
> - Red Hat Linux 9
> - Recompiled the kernel, Linux-2.4.21, included the
> low-latency and preempt patch
> (/proc/sys/kernel/lowlatency shows 1)
> - Before compiling any software, I set CFLAGS and
> CPPFLAGS to -march=athlon-xp
> - MythTV 0.11
> - Killed off as many of Red Hat's services as possible
> - Using twm as the window manager.
>
> hdparm -Tt shows:
> /dev/hda:
>  Timing buffer-cache reads:   128 MB in  0.41 seconds
> =312.20 MB/sec
>  Timing buffered disk reads:  64 MB in  1.42 seconds =
> 45.07 MB/sec
>
> I'm using ext3 filesystems for everything, two
> partitions, one for root, one for /home. which is
> where MythTV files are stores (using symlinks from
> /mnt/store).  The ext3 filesystem is mounted with
> noatime, and in grub.conf, I put in
> rootflags=data=writeback.
>
> I'm not really stressing things out, I'm recording
> RTJPEG at 480x480, MP3 quality 7.  Switching to MPEG4
> (as suggested in a post in the mailing-list) didn't
> help any.  I have plenty of CPU time (it never goes
> higher than 50% user, never less than 30% idle.  Not
> using jitter control, not using experimental A/V sync,
> just using the default options.
>
> The only thing that I can think might possibly causing
> some problems is that I have only one hard drive for
> everything.  Either that, or I do I need a real 2.4GHz
> machine (i.e. Intel?)
>
> Please folks, any suggestions?  Any at all?
>
> -- Joe
>
> --- Joe V <joevph at yahoo.com> wrote:
>> Brian,
>>
>> Well, it helps a bit...  I upgraded to bttv 0.7.107
>> (and specigied gbuffers=10), put my hard drive and
>> DVD-ROM on seperate cables (don't know if that will
>> help much), as well as forcing 32-bit operations,
>> and
>> the stutters, when they happen don't cause such as
>> big
>> of a delay.
>>
>> I don't recall any stutters last night when I put my
>> DDR400 module (running at DDR266) from my desktop in
>> the machine with those changes (watching for a good
>> 30
>> minutes), so it could be a memory bandwidth issue as
>> well as a bttv driver issue (and maybe the HD).
>>
>> I'll keep experimenting and see what works.
>>
>> Are you using your machine as just a frontend, or as
>> both frontend and backend (as I'm doing)?
>>
>> -- Joe
>>
>> --- Brian <brian at boid.isa-geek.com> wrote:
>>>
>>> I'm having no issues running .11 with a k7s5a,
>> duron
>>> 1.1, 512mb of pc133, ata100 drives, TV Wonder VE,
>>> generic 2.4.21, bttv 0.7.107 (Could not get 0.9.x
>> to
>>> run properly)
>>>
>>> Hope this can help point you in the right
>> direction
>>> :/
>>>
>>> Cheerios
>>>
>>> :)
>>>
>>> On Sat, 16 Aug 2003 23:37:16 -0700 (PDT)
>>> Joe V <joevph at yahoo.com> wrote:
>>>
>>>> This is completely strange, I don't understand
>> it.
>>>>
>>>> I upgraded to an AMD Athlon XP 2400+ (real
>> speed,
>>>> 2GHz), with an ECS KS57A Pro motherboard today.
>>> The
>>>> motherboard isn't the greatest, but for $89.99
>> for
>>> the
>>>> combo, you can't really beat that.
>>>>
>>>> Anyway, I have my profile for Live TV setup for
>>>> 480x480, RTJPEG, MP3 Audio compression, level 4
>>>> (middle of the pack or so).  When I run "top", I
>>> see
>>>> that mythbackend ranges from 20-43% (CPU), and
>>> that
>>>> mythfrontend ranges from 3-15%.  I have DMA
>>> enabled on
>>>> my hard drive (hdparm shows this), XVideo is
>>> enabled
>>>> on the second head of the Matrox G400 I'm using.
>>
>>> The
>>>> card being used is a Leadtek Winfast TV XP 2000
>>> Deluxe
>>>> (bttv), and I'm using the 2.4.21 kernel,
>> unpatched
>>>> from kernel.org.
>>>>
>>>> Despite this, I still get a stutter in the
>>> video/audio
>>>> every now and then (if you average it out,
>>> probably
>>>> once every ten minutes).  The output of "top"
>>> doesn't
>>>> seem to spike any, so I don't think that it's
>> the
>>> CPU
>>>> not being powerful enough (it should be).
>>>>
>>>> I've tried a bunch of things...  Swapping RAM
>>>> (currently I'm using PC133, but I took the
>> DDR400
>>> from
>>>> my desktop out and tried it), I've tried not
>>> enabling
>>>> the second head on the Matrox (using a monitor),
>>> using
>>>> ALSA and OSS, using KDE and Blackbox, heck,
>> almost
>>>> everything I could think of except changing the
>>> video
>>>> card (maybe that's it?).  I've also turned off
>>>> unnecessary services in Red Hat 9 (turned off
>>>> sendmail, cups, etc.).
>>>>
>>>> Does anybody have any further suggestions?  At
>>> this
>>>> point, I'm almost suspecting a hardware problem
>> of
>>>> some sort.
>>>>
>>>> -- Joe
>>>>
>>>> __________________________________
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>>>
>>> -- 
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>>> ----
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