[mythtv-users] Can an Atom D525 handle a frontend and a slave backend with dual ota hd tuners?

Raymond Wagner raymond at wagnerrp.com
Thu Apr 7 17:54:02 UTC 2011

On 4/7/2011 13:37, jedi wrote:
> On Thu, Apr 07, 2011 at 12:39:12PM -0400, Raymond Wagner wrote:
>> On 4/7/2011 09:47, Marc Sherman wrote:
>>> On 4/7/2011 9:03 AM, Richard Morton wrote:
>>>> By using an atom as a backend you are below the recommended spec and when/if
>>>> the scheduler runs (due to new recordrule, mythfilldatabase or eit data) the
>>>> cpu will be the bottleneck and playback will almost certainly stutter.
>>> Does that apply to my usecase? All the scheduling and database
>>> management is done strictly in the primary backend, right? I'd be
>>> keeping the mbe on my basement server, only running a slave upstairs on
>>> the atom.
> ...rerunning the scheduler doesn't seem to bother any of my frontends that
> are all ION boxes and my combo BE/FE that is an ION box. The crapulence of
> the Atom certainly may pose a problem but it tends to get overblown by some
> people.
>     My master backend is "beefy" but most of my other myth boxes are not.

The scheduler comments have nothing to do with the frontend or slave 
backends, but solely with the primary backend and database.  The 
scheduler is a single threaded algorithm and a modern processor is 
easily 4x faster at single threaded operations than an Atom.  The 
scheduler 'problem' is two fold.

First, while the scheduler is running, all other MySQL accesses and 
processing will be slowed.  Things like opening the Watch Recordings 
screen, or scrolling through the EPG, may take more time.  If your MySQL 
database is on the same drive as other storage, things like accessing a 
series of channel icons may be slowed.

Second, there is a cutoff somewhere around a minute where if the 
scheduler is running beyond that duration, it will begin to hold up 
recordings with late starts.  This gets to be an issue with users 
running multiple digital and virtual tuners, or users with digital large 
cable lineups.  The same run that might take 15 seconds on a modern CPU 
will risk exceeding the time limits on an Atom.

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