[mythtv-users] which Mythbuntu ISO - Zotac ZBOX ID41

[Gary Buhrmaster]

On Tue, Nov 4, 2014 at 5:46 PM, jedi <jedi at mishnet.org> wrote:
> On Tue, Nov 04, 2014 at 08:22:23AM -0800, Thomas Mashos wrote:
....
>> Isn't it already recommended to run MythTV with more than 2GB of RAM?
>
>     I certainly hope not as I have a house full of perfectly useful ION
> boxes with only 2G of RAM.

There is often a difference between "recommended" and
"tolerable" and "it might boot" (if you wait long enough).
And it also depends on how much of your memory
is "leveraged" by various hardware resources (like the
GPU).  And then there is the memory footprint of your
application.  All leading to the "Your experience will vary"
response.

I believe the 32bit recommendation for systems with
less than 2G of memory is part of the "your experience
will vary" rule.  While it is true that various parts of the
OS and apps will be "larger" when running in 64bit
mode (putting additional pressure on available memory),
the additional registers available can result in faster
performance (which is more likely to be of interest on
older systems).  That all said, there were certain Intel
Core 2 processors that ran certain codes slower in 64bit
mode(*) (I believe jya built for 32bit on the mac for this
reason).  And, one should note that these days most
software is mostly tested by people running on 64bit
machines. So some bugs (such as the recent commflag
bug discovered by faginbagin) only occurs on platforms
not as well tested.  Lastly, some major vendors have
dropped 32bit support in their enterprise distributions,
resulting in yet additional lack of attention to edge
cases that only occur there.  On the other side, there
are some (usually legacy proprietary) drivers that only
work in 32bit systems.  You can run a 32bit system
with up to 64GB of real memory using PAE (if the
hardware supports it).

So, 64 bit vs 32 bit: You make your choices, and
take your chances.  Unless you are right on the
edge, I would generally choose a 64bit install.  But,
"Your experience will vary".

Gary

(*) As I recall, the Core 2 (in 64bit mode) was unable
fuse instructions into a single micro-op, and the decode
engine could occasionally starve the pipeline due to
the line fetch requirement.