[mythtv-users] CPU power and decoding

Stephen Tait tait at digitallaw.co.uk
Thu Oct 7 20:58:11 UTC 2004

At 17:57 07/10/2004, you wrote:
>>This depends on the tuner card as well: hardware MPEG cards like the
>>Hauppauge, AVer 179 and Yuan do indeed consume little horsepower
>>because, like the DVB cards, they output precompressed MPEG-2 -- they
>>do it by having an onboard co-processor that does the hard work,
>>converting electricty into heat.
>This is an important point. I'd like to guess how much GHz CPU cycles 
>(very approximately) difference is there.
>Could you please compare
>- a PVR-250 with AMD Athlon 3GHz,
>- a Pinnacle PCTV Pro  with AMD Athlon 3GHz?
>When I want to record a broadcasting, and do commercial skipping, how much 
>CPU cycles (GHz, rough estimate) would be left for other unrelated tasks 
>on the PC ?

Put it this way;

I've got a PVR-250, an Athlon 2400 and an nVidia MX4000. Recording takes no 
more than 1% CPU, playing back takes no more than 1% CPU (according to 
top). Commflagging takes up about 15% CPU. To put it blunty, pretty much 
any CPU you can buy today is vastly overpowered for Myth related 
activities. You only ever need CPU horsepower of this magnitude if you're 
software encoding multiple streams to MPEG4 or playing back HDTV.

You only really need the CPU power for [en|trans]coding movies or music, or 
for fullscreen goom.

Save the money on CPU and sink it into more hard drives or tuner cards. 

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