Troubleshooting:Performance

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Revision as of 21:12, 30 September 2007 by Nordle (talk | contribs)

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What?

MythTV, as with any software, works better if the hardware is working well.

Currently this is just a simple list of things to check, hopefully "how" they are checked will be added later. But currently this might be helpful, even in its basic form.

Essentially were looking at minimising latency and maximising throughput by enabling hardware acceleration where possible.


CPU: AMD Athlon64-3700
MOBO: Asus K8VSE (VIA K8T800)
RAM: 1GB DDR400 (single channel)
GPU: NVidia 6800GX 128MB AGP (NVidia Driver Linux-x86-100.14.19)
HD: Western Digital WD200JB (200GB)
DISTRO: Slackware 11.0
KERNEL: 2.6.22.9


Where?

Where do we start looking to achieve performance zen. We could look at the symptoms, but this all takes time. So listed are simply some of the areas which might impact on video playback judder.

  • PC's Bios
Default Settings.
Start off by not overclocking, don't run in turbo mode. Performance is nothing without stability. Once your system is working, you can return to the overclocked setting.
AGP Fast Writes.
Enable / disable. For some motherboards, enabling this option causes instability, it should help improve performance when enabled.
PCI Latency.
Set to lowest setting and gradually increase it if there are extra issues.
  • Kernel
Drivers.
Assuming a proprietary graphics card is being used, make use of the official drivers from the manufacturer. And make sure your cards GPU is listed as being supported with the driver version.
Timer Frequency.
By setting the kernel to use 1000HZ, it is suitable for both PAL and NTSC playback / recording.
Preempt.
Disable kernel preemption. Some people report faster systems with preemption enabled, but it might interrupt video playback more than it helps.
  • Userland
DMA.
If your disks can use it (and they really should), make sure DMA (Direct Memory Access) is enabled.
xorg.conf
The X-Server's configuration can be used to control all sorts of settings, some of which impact greatly on the playback of video.


There are many more in the list, this is just a basic start.


How?

Ahh yes, the detailed explanation of how. This takes a while, so I thought it best to just list various items first, as at least these give a reference point, some keywords which can be googled in the meantime. The how will follow.