[mythtv-users] Trouble with HD playback

Yan-Fa Li yanfali at best.com
Fri Nov 12 05:21:30 UTC 2004

Hi Vito,

very interesting paper.  I looked at the conclusions and it seems to 
indicate it's not memory or CPU bandwidth that improves the HDTV 
performance, it's ordering of instructions and data retrieval to 
optimize cache usage plus the use of MMX type instructions which causes 
a 4 fold increase in performance.  You need to write the software 
correctly so it can access the memory and instructions in the right 
order so to speak to improve cache usage.  If memory bandwidth and clock 
speed were the whole thing then a P4 3GHz wouldn't get it's ass kicked 
by an Opteron at 1.8GHz, clocked at over 1GHz slower would it.

After all they got a P3 933 to decode 1024x768 HDTV video just fine...
It's not the size of your boat, it's the motion of your ocean :D

Anthony Vito wrote:
> All papers, numbers, and theory aside.... The simple fact is that
> every last little bit of performance helps when you're putting
> together and HDTV system. My experiences and what I've read here
> indicate there is a lot more to do with hardware "playing nice" they
> actual performance numbers.(people with FX53's getting jittery
> playback) If you can come up with an XP3000x266/board/video/ram combo
> that can play back HDTV as smooth as my bottle of vodka, we would
> would all benefit from it. I have an overclocked 2800MP(<100USD) chip
> doing it, using onboard video ( which makes the FSB even more
> important for my setup )... So a proverbial "Show me the hardware!" is
> left to you.

I don't have HDTV sadly yet.  As soon as I do I will try with what's 
available, but I would probably use an AMD 64 1.8GHz @ 2700.



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