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

[Pieter De Wit]

On Sun, 13 May 2012, Joseph Fry wrote:

> 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.

Perfect - this is what I wanted to know :)

I wasn't sure about the LiveTV aspect, but that cleared it up.

Thanks,

Pieter