[mythtv-users] Dual-CPU/Core & MythTV

Galen galen at myhome.net
Mon May 9 19:56:07 UTC 2005


Sounds like a neat setup... anybody else have thoughts/experiences?

-Galen

On May 7, 2005, at 6:19 PM, Devan Lippman wrote:

> I run dual CPUs on my backend and I think if you've got the cash its
> an awesome way to do things.  I have two P3 Tualatin 1.3GHz CPUs and
> capture HDTV off my STB using firewire with no problem while running
> transcoding and commercial flagging and streaming to the frontend.  I
> like how it makes it so a really busy thread can get its own CPU and
> the other threads are happy running on the other CPU.
>
> Devan
>
> On 5/7/05, Galen <galen at myhome.net> wrote:
>
>> Been checking on the hardware... please correct me if I'm wrong here!
>>
>> The potentially cost-viable CPU options with a few sample prices
>> attached:
>> 1) AMD Athlon MP (2800 2.13 GHz = USD ~197, can't find anything  
>> faster)
>> 2) AMD Opteron (242 1.6 GHz = USD ~158, 244 1.8 GHz = USD ~203)
>> 3) Intel Xenon (2.8 GHz = USD ~220, 2.66 GHz = USD ~199)
>> (did I miss any cost-viable options?)
>>
>> For each of these CPUs, what would the comfortable minimum be for
>> HDTV playback only? (I will have an GeForce card, but I believe that
>> I will lose XvMC acceleration if I want to do any fancy deinerlacing
>> tricks. Is this correct?) I am trying to assess the price difference
>> and practicality of a dual-CPU setup. Also, what anybody know sort of
>> heat production are we talking about per-CPU here?
>>
>> Does MythTV compile properly for 64-bit and actually offer any
>> practical performance gains? (Or am I going to completely regret that
>> I even *thought* of trying 64-bit code... I am thinking that may be a
>> "yes" for the time being...)
>>
>> -Galen
>>
>> On May 7, 2005, at 3:03 PM, Galen wrote:
>>
>>
>>> I'm one of those lurkers... I'm not yet in possession of my own
>>> MythTV box, but I'm rather familiar with *nix and am working on
>>> plans (and finances) for an awesome HDTV MythTV box. When I get it
>>> done, it will be killer. (I am, however, somewhat of a newbie when
>>> it comes to x86 hardware. I've lived in RISC land too long...)
>>>
>>> I've been looking into the specifications for a MythTV system, and
>>> it occurred to me, it seems like an awesome application for a dual-
>>> CPU/core setup. HDTV decoding is pretty high-end in terms of system
>>> demands, so purchasing much more CPU than required for decent HDTV
>>> playback (~A64 3200, P4 3 GHz) gets really expensive, really fast,
>>> and it's simply impossible to purchase twice the CPU required for
>>> HDTV playback w/decent de-interlacing and various other functions.
>>> More CPU means you can do more post-processing, commercial
>>> flagging, maybe even background transcoding (with the proper nice
>>> values, of course).
>>>
>>> It seems like a dual-CPU system would be an excellent solution to
>>> this problem. Size the CPUs such that one CPU is able to
>>> comfortably handle the single largest realtime function (HDTV
>>> decoding), and then the other CPU is free so you can do some
>>> *awesome* de-interlacing, commercial flagging, etc without ever
>>> impacting the HDTV playback. The same effect would happen with dual
>>> core CPUs, but they are only getting started. Dual CPUs are here,
>>> today. I've done enough work with dual-CPU systems to realize that
>>> while they don't offer "double" the performance for traditional
>>> mono-threaded applications, for some multi-threaded applications
>>> that rely on realtime response (i.e. video playback), they're
>>> better than a CPU that's twice as fast.
>>>
>>> Does this make sense? I'm curious if anybody has tried this, and
>>> with what CPU/motherboard? Any thoughts as to some optimal hardware
>>> configurations (CPU speed/type/mobo)? What would my practical
>>> options for de-interlacing be with a setup like this?
>>>
>>> -Galen


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