[mythtv-users] Best Cheap processor

Rod Smith mythtv at rodsbooks.com
Fri Feb 16 02:44:57 UTC 2007

On Thursday 15 February 2007 15:32, Mitchell Gore wrote:
> Hi,I want to build a cheap SD Myth box.  What would you suggest the best
> processor would be?AMD Sempron (cheapest)Intel Celeron?Also what speeds
> would you recommend? A Sempron 64 2800+ 1.6Ghz starts at $27.99!  Would
> that work?  I plan on using a S-video out on a Nvidia card (hopefully
> without XvMC) and a PVR-150 card.Thanks,Mitchell

On my 3.06GHz Intel Celeron, playing back SD content generally consumes about 
30% of my CPU power, although details vary depending on the video card and 
various playback options. Thus, for playback I'd say anything 1GHz or better 
should be fine (Intel speeds; AMDs are faster on a GHz-to-GHz basis, so pay 
attention to the "####+" model number instead). By that standard, an AMD 
Sempron 2800+ should be more than fast enough -- that should be pretty close 
in speed to my Celeron, in fact. This would be marginal for playing back HD 
content, though. If you think you might want to upgrade to HD in the future, 
I recommend you get a motherboard that will accept a CPU that's faster than 
3GHz (again, Intel speeds).

VIA makes some inexpensive ~1-1.5GHz x86 CPUs that are generally sold 
pre-mounted on motherboards. If you're looking for a low-budget box, you 
might consider one of those, but I can't guarantee they wouldn't have any 
other problems. In theory they should be fast enough for playback, though. If 
you're interested, try doing some more research on these CPUs and 

Recording from a frame grabber (software-encoding capture card) chews up CPU 
time at a rate that's similar to the playback demands -- but again, this 
depends on the resolution, encoding method, encoding quality, etc. If you're 
going for a low-budget CPU, you should try to get a hardware-accelerated 
encoding card. One low-cost model is the Hauppauge WinTV-PVR 150, but some of 
these have been substituted at the factory with a model that doesn't work 
with MythTV, so buy locally from a store with a good return policy. 
Hardware-encoding cards do most of the work of encoding the video, dropping 
the CPU load down to almost nothing. This is particularly important with a 
weaker CPU and/or if you want to have multiple tuners. With a 1GHz CPU, you 
might not have the CPU power to both record and play back video at the same 
time without a hardware-encoding card. OTOH, hardware-encoding cards 
generally cost a bit more than software-encoding cards.

Rod Smith

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