[mythtv-users] First build - Looking for CPU recommendations

[Chris]

>>
>> Why 3 separates vs. a PVR-500 and a single 150? Wondering if there's
>> any reason why I should instead go with 2 separate 150's vs. the
>> single 500.
>>
> 
> I really didn't look into the 500.. so I just went with what I knew.
> Although 2x 150's is still cheaper then 1 500.
> 

Just to add a taste of real-life experience - I set up Mythtv on a 
Gigabyte uATX board and have discovered that the board is too small and 
I will have to change to something with more slots.

I chose to go with a P4 3.0Gb Northwood core because I wanted to keep 
heat dissipation to a reasonable level.  That has worked beautifully as 
I find that I can simultaneously record and watch 1080i with perfect 
smoothness and reasonable cpu reserve.  Almost any 3.0 Northwood can be 
overclocked to 3.2 if needed, but I just don't need it.  My HD tuner is 
a pcHDTV3000.  SD uses Hauppauge PVR-350.

I chose a FX5200 graphics card because it is all you need for HD and 
handles XvMC very well.  That is important for keeping cpu workload 
down.  Recording/watching 1080i without XvMC I see utilization peaks 
nearing 80%.  With XvMC, utilization is much steadier at just a tad over 
30%.  Since the HD data stream is MPG2 and the Hauppauge cards output 
MPG2, recording doesn't stress the cpu.  Playback is what works the cpu 
and whatever you can offload to the graphics card is money in your 
pocket.  I've seen no evidence that either 64 bit or x2 adds anything to 
Mythtv and if using a P4 gives you a better choice of motherboards, 
don't rule it out.

A thought or two about tuners.  My pcHDTV3000 does a fine job with OTA 
HDTV, but the built-in SD tuner leaves a lot to be desired and is not a 
good match performance-wise with the PVR cards.  I'd have done better to 
have chosen an HD only tuner and saved some bucks.

The PVR-350 is a fine card but I'll probably never use the onboard MPG 
decoder so I could have saved some bucks there.  VHF-TV is supposed to 
disappear in the US pretty soon so VHF tuners are going to have a pretty 
limited usefulness unless they also have good video capture 
capabilities.  You need to think in terms of what your video sources are 
likely to be and plan for that.  Running video through a modulator so a 
tuner card can see it on channel 3 or 4 and then demodulating it is not 
likely to give a very good viewing experience on a HDTV capable set.