[mythtv-gta]: Re:Raspberry PI vs. VIA APC vs. ?

[D. Hugh Redelmeier]

| From: Lennart Sorensen <lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org>

| On Mon, Jun 18, 2012 at 11:21:10AM -0400, Tom Lichti wrote:
| > Let us know how that goes. 800MHz ARM is not all that fast, I'd prefer
| > 1.5GHz at a minimum.

To think, I first used X extensively on a 68020 running at 20 MHz.

| It may not be fast, but with a decent video engine, decoding video ought
| to not be a problem.  Certainly 1080p60 x264 playback on my I.MX53 QSB
| which is 1GHz uses less than 40% CPU.

Beware things not covered by supplied CODECs.  I have a WDTV Live that
doesn't get along with my Myth Backend and it won't even say why, just
that the encoding isn't supported (probably).

| Not a lot of 1.5GHz ARM systems around.
| 
| But of course ARM isn't x86, it's much better.

In what way?

My impression is that modern x86 systems (possibly excipting
Atom) do more per cycle than Arm systems.  It probably starts with a
much higher-performance memory system (wider, larger, larger caches,
better caching algorithms).  Note: "impression", not fact.

After I wrote that, I googled a bit but didn't find anything great.
Here's one useful article from the end of last year.  Not that it is
comparing a new ARM system with ancient non-Atom X86 (Pentim M
@ 1.86 GHz, Core Duo T2400 @ 1.83 GHz).

<http://www.phoronix.com/scan.php?page=article&item=pandaboard_es&num=1>

My tentative world view is:

ARM SOCs are cheap, low power, flexible, ubiquitous, well supported.
A great choice for a lot of designs.  Great for embedding, great for
appliances.

x86 systems are standardized, cheap, fast, well-supported, ubiquitous.
A great choice for general purpose computing.

The disputed territory is mostly on the boundary of those two markets.

A Myth Box is actually a mixture of those two markets.  Myth is a
funny beast: it is an appliance built by end users and intended to be
built and customized by end users.  Replication is much looser than
most appliances.

I want a Myth appliance.  But most appliances:

(a) resist end-user programming.  There are ARM systems that try, but
    none is as easy as a PC.  In particular, the lack of
    standardization reduces the leverage of a distro like MythBuntu.
    This will become better if Myth developers gravitate towards
    one particular ARM system.

(b) don't have as much Video, RAM, and disk space, and performance as
    MythTV has become accustomed to.

Oh, and the video driver situation on ARM is mostly worse than on X86.

Once you kit out an ARM to be comfortable for Myth, it starts to be in
enemy territory.  I have a few X86 systems for running Myth front-ends
and they each cost about $200 plus tax.  An ARM system useful for
MythTV isn't likely to be much cheaper and convenient soon.  Note:
nobody had to produce a distro specific to my X86 boxes since they are
just PCs as far as the software is concerned.

I admit that I bought these at good prices, hard to duplicate.  But
then again, I bought some of them three years ago so price/performance
ought to have decreased.  It may not have -- the "nettop" seems to have
lost favour.  Perhaps that is because they are approaching enemy
territory (appliancehood).

Why are nettops unpopular?  Is it because they are seen as
half-powered PCs?  After all, the somewhat similar Mac Mini does seem
to be popular (full priced, full powered, but tiny and cute).  Or are
they viewed as purposeless appliances (they come out of the box with
no applications)?
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