[mythtv-users] What parts does the frontend do ?

[Joseph Fry]

On Sun, May 13, 2012 at 4:48 PM, Pieter De Wit <pieter at insync.za.net> wrote:

> Hi Guys,
>
> I see the previous post is regarding a low noise frontend. This lead me to
> finally post a burning question I have had for a while:
>
> Where can I find out what tasks are performed by the frontend ?
>
> This might sounds stupid at first, but here is my setup I would like to
> propose:
>
> Back-end - All the storage and the DVB-S2 cards, powerfull yet hidden away
> somewhere out of earshot.
>
> Front-end - Good network connection to the back-end, good display card.
> Silent and slow (?) disk - perhaps even a 16gig Flash card instead of disk
>
> Now, when watching livetv, I assume that the ring-buffer is created as
> part of the frontend ? (NFS can help with this) How much of tasks can be
> offloaded to the Back-end ?
>
>
Your assumption is incorrect. All the Frontend does is play the stream from
the network, it doesn't actually cache anything to disk itself.  I have
frontends that PXE boot and have no storage at all.  Now that's not to say
that the frontend doesn't need some horsepower; depending upon your theme,
number of channels, etc. you may need 1GB or more RAM for adequate
performance.  Additionally, if your not using some technology to offload
decoding of the video, you might need a powerful processor to decode the
video.

There are many people here using cheap Nvidia ION/Atom based PC's, with no
local storage (other than perhaps a USB flash drive to boot from), and only
a GB of RAM and seeing great performance from them.  The ION chipset will
decode most video content in the GPU, so the low end CPU is adequate to run
the frontend.

A 100MB network is plenty fast enough for a mythtv setup... no need for
Gigabit.  If you use network based tuners, you might need to go gigabit if
you plan to have more than a couple of tuners... or do what I did; I put a
couple of cheap 100Mbit NIC in my backend and connected my HDHomeRun tuners
direct to the backend so they don't cause any network load at all for the
rest of the network. so my 100Mb network never caused a problem with 4-6
frontends in this arrangement.

Essentially, the frontend is just a client... does very little work of it's
own other than rendering the video.
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