[mythtv-users] 32 vs. 64 bit, any significant difference?

sonofzev at iinet.net.au sonofzev at iinet.net.au
Fri Dec 18 04:39:02 UTC 2009

On Fri Dec 18 14:39 , f-myth-users at media.mit.edu sent:

>    > Date: Thu, 17 Dec 2009 15:52:14 -0600
>    > From: Johnny Walker johnnyjboss at gmail.com>
>    > > I have an old 0.20 combo BE/FE machine with 2 GB of RAM in it, and I've
>    > > never it seen it use more than 1GB. I'm now sorry I put that extra GB
into it.
>    > >
>    > > Unless you are using it for something else in addition to Myth, there's not
>    > > much point in even 4GB in a Myth machine.
>    > I'm surprised to hear that - MythWeb (Apache) and MySQL use up 1Gb of
>    > memory running the canned all movies search for me. Maybe you don't
>    > have as many channels as I do.
>e was young.
>So far, with 2GB in it, no problem.  This is all SD on a master
>backend with no frontend; that's a different box.  But I've probably
>got an unusual configuration.
>[By "terribly", I mean 8+ minutes -per scheduler run-.  With more
>memory, it now takes about 90 seconds start to finish, including both
>the MySQL-heavy phase (~40s) and the mythbackend-heavy phase (~50s),
>and more the first time the scheduler has run in a while (because it
>can spend up to an additional 30-50s paging in all the MySQL tables
>if they've been flushed out to disk in favor of filesystem buffering
>for video files.)  But I've got a lot of recording rules and it's an
>Athlon 2800+.  Various improvements also went into the scheduler in
>later releases, so I expect this to improve when I upgrade.)

My current configuration has a headless MBE with 2 RAID 5 arrays using XFE (and
optimisations for the recording partition that take up additional RAM). 3 tuners
set to record up to 2 channels each (on the same multiplex) a vast video and
music library and is running a webserver (lighttpd) for mythweb and some other
small sites... 

I have 4GB of RAM but haven't seen it use much more than 1 GB of user RAM..
This box is 64GB... My frontends both have 2 GB of RAM but it is more to get dual
channel performance than for the extra RAM as I barely use more than 1 GB.. )

BTW my MBE is 64 bit and my FE's are 32 bit.. 

However, one of my FE's used to be 32 bit and with 3 tuners (but only allowing 1
channel per tuner) I had one recording drive locally and one on the network via
NFS v3  .. the machine never complained of any RAM issues.. 

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