[SunRescue] MP3s

[Martin Frost]

James Lockwood wrote:

> The microSPARC CPU's aren't directly comparable to any PC system
> architecture.  The basic design includes a fast main memory bus and
> a very small cache.  The cache isn't much of a bottleneck as there
> is an extremely low cache miss cost.  Compare this to the SuperSPARC
> line which is comparable to the Pentium in many ways, large caches
> with a higher cache miss cost.

I was basing my comparison on the fact that I found some Java software
that I wrote a couple of years ago ran at roughly the same speed (within
10-20%) on an SS5/110 and my 486/100. I never did any proper sort of
benchmarking, though, so this could have been down to other factors (or
it could have been a slower SS5 without me realising).

> I would recommend having a main server "play" the MP3's and send raw
> data through the network to a local audio receiver (like NAS).  A 486
> would be able to do this with no problem, and you need under 2mbps of
> bandwidth for each stereo audio stream at full quality.  A lower
> bandwidth alternative would be to have the "server" decode the MP3's
> and run them through a simple compression filter (an RLE like Huffman
> would be my first choice for a slow CPU though you might find that
> other alternatives are satisfactory).

This was my backup solution, but I was worried about the bandwidth if
I want three or four going at once on 10Mb ethernet. I'd considered
various compression schemes, and would probably use Huffman-encoded
deltas (possibly splitting the 16-bit deltas into high and low parts
and Huffman-encoding them separately).

> SS5 audio is CS4231, LX is DBRI/CS4215.  They both have the same
> capabilities (48MHz 16bit stereo), the SS5 doesn't include ISDN and is
> cheaper to manufacture.

Does that mean that LX audio has a higher CPU hit?

My main non-ideological reason for preferring Suns to PCs in this case
is that they are easier to netboot. On the PCs I'd probably end up
booting from floppy rather than network!

My main reason for preferring the LX to anything else (including the
SS5, which would otherwise be ideal) is its size. PCs in particular
are not a friendly size for hiding away on a shelf. ;)

--m