[mythtv-users] Re: HDTV, Myth, HD-2000, HD-3000, questions galore (and hopefully answers from the smart people... )

Brad Templeton brad+myth at templetons.com
Fri Jan 28 03:45:38 EST 2005


On Thu, Jan 27, 2005 at 11:46:08PM -0600, Paul Leppert wrote:
> When watching livetv on ABC (HD 720p), I end up with 0% idle using top
>     72% cpu usage for mythfrontend
>     18% cpu for mythbackend
>      6% for X
>      1% for lirc_dev
>     <1% for top and others
> 
> When watching livetv on NBC (HD 1080i), I end up with 0% idle using top
>     82% cpu usage for mythfrontend
>      9% cpu for mythbackend
>      7% for X
>      1% for lirc_dev
>     <1% for the rest
> 
> When watching recorded Fox (no recording), I end up with 10% idle using top
>      56% cpu usage for mythfrontend
>      24% for mythbackend
>       5% for X
>       1% for lirc_dev
>       <1% for the rest
> 
> When watching recorded NBC (no recording), I end up with 0% idle using top
>      85% cpu usage for mythfrontend
>      10% for X
>       2% for mythbackend
>       1% for lirc_dev
>       <1% for the rest
> 
> These numbers seem much worse than what I've read from other people
> online.  What are others seeing with HDTV?  Should I be getting better

Yes, they are worse.  Though actually my Athlon-3K system is currently
doing 100% saturation because I am going through more nvidia driver
problems and booting it without AGP, so I get saturation but all the CPU
is in the X server.

Surprised to see much CPU in the back end, that I don't normally see
when it's recording.  All it has to do is demux the atsc stream and write
to disk.   Have not tried the 1.6 drivers, they reported it doesn't work
well on 2.6.10 in the release notes for that driver.

Is it possible you have some sort of memory bottleneck?  How's your
memory bandwidth?  Try bw_mem in lmbench or memtest86.


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