[mythtv-users] SLIM vs, CPU--

Allen Edwards allen.p.edwards at gmail.com
Fri Oct 3 17:26:39 UTC 2008

On Thu, Oct 2, 2008 at 10:27 PM, Brad DerManouelian
<myth at dermanouelian.com> wrote:
> On Oct 2, 2008, at 10:15 PM, Allen Edwards wrote:
>> On Wed, Oct 1, 2008 at 12:44 PM, Brad DerManouelian
>> <myth at dermanouelian.com> wrote:
>>> On Oct 1, 2008, at 12:08 PM, Allen Edwards wrote:
>>>> On Wed, Oct 1, 2008 at 10:06 AM, Brad DerManouelian
>>>> <myth at dermanouelian.com> wrote:
>>>>> On Oct 1, 2008, at 8:59 AM, Allen Edwards wrote:
>>>>>> anyone?
>>>>> All the default playback profiles are spelled out here:
>>>>> http://www.mythtv.org/wiki/index.php/Playback_profiles
>>>> I guess I should have said in my original post that I had read all
>>>> that and more.  If you read that, you will come to the conclusion
>>>> that
>>>> CPU-- would be less CPU intensive than slim but I am seeing the
>>>> opposite.  That was my question.  Sorry I was not clear.
>>> That depends. If you're using PVR-350 and CPU-- and not playing back
>>> MP2 recordings under 720x576, it would be MUCH more CPU intensive.
>>> If XvMC isn't working correctly on your system, CPU-- would also be
>>> more CPU intensive.
>>> deinterlacers can use a lot of CPU if you're viewing interlaced
>>> content.
>>> You mention audio skips. Is this only when viewing the OSD? This is
>>> common with XvMC and the bob deinterlacer. Is this how you are
>>> determining your CPU usage using each profile? What does top say
>>> about
>>> your CPU when using each profile?
>>> Bottom line is that there are way too many variables to tell you why
>>> you're seeing what you're seeing - especially with the information
>>> you've given about the content you're playing back (ATSC HD - that
>>> could mean about a hundred things)
>>> The way to figure out what's really happening is to look at your
>>> frontend logs to see exactly what features are being used, then play
>>> back the same content with the other playback profile and see which
>>> features are being used and determine from there where the issue
>>> lies.
>>> Could be as simple as not having UseEvents True in your xorg.conf
>>> file. :)
>>> -Brad
>> I do not have a PVR-350.  I have a Nvidia 6200 for the XvMC.
>> I finally got around to doing a little experimenting.  Basically, I
>> played the show in SLIM and the CPU% for mythfrontend was about 75%.
>> I then switched to XvMC and the CPU went down to about 47% but there
>> was no stuttering.  I got out of the show and started it again and the
>> CPU% was 93% and the stuttering was back.  mythfrontend.log showed
>> prebuffering pause under this high CPU% but not under the other two
>> conditions.  I didn't start any other processes so don'w know what is
>> going on.
>> Strange.
> Update your nvidia driver and make sure you're using the latest code
> from -fixes. There was a bug a while back about playing a video, then
> playing it again and getting big CPU usage the second time. I don't
> remember if it was resolved in an nvidia update or mythtv update, but
> it has since been resolved.

Thank you!  I did as you said and all seems well now.


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