Re: [OT] (A little) : Firewire cables...

[Jim Noble <yahoo-groups@xxxxxxxxxxxxxxxxxx>]

Phil Harris wrote:
>> I really don't understand why Apple haven't produced a "Mac
Midi" that
>> has a bit of expansion space (say, 2x3.5"HD, x16PCIe, x4PCIe,
2xFW800,
>> etc, maybe even dual cpu). It's a really big hole in their
lineup...
>>
> Well I think the idea is that the iMac is supposed to fill that gap
but I
> don't "need" anything with a built in display ...
>

Indeed. The iMac serves a different market.
> I would love a PowerMac as they are damn sexy looking but they are
quite
> large (physically) for not a huge amount of expandability (basically a
Dual
> G5 PowerMac can only take two hard discs IIRC) so it's only real
advantage
> to me over a Mac Mini is the gigabit Ethernet and the ability to whack
in
> some Firewire800 (or maybe eSATA) cards.
> With the Intel Dual Core Mac Minis from £399 (including gigabit
LAN and more
> than enough processing grunt for what I use) then effectively paying
another
> £1,000 for new PowerMac for pretty much just a couple of
additional
> Firewire800 ports doesn't seem a great bargain...
>

Except you can't buy PowerMacs new any more (AFAIK). The Mac Pro has 4
drive bays btw (but quad/octo-core is definitely overkill for simple
file serving!)

> If firewire and USB are out (and
> eSATA is out due to difficulties in getting enough eSATA channels out
of an
> enclosure) then it's down to getting enough SATA channels available
inside
> an enclosure (really I'd want provision for 12 data drives as well as
boot
> and optical drives), getting a big enough enclosure and sorting out
drive
> caddies/backplanes at that ever-important "UKHA_D price".
:-D
>

I just recently discovered that SATA port multipliers and multi-lane
SATA exist. The latter merges 4 channels into a single connector. Port
multipliers expand a single SATA connection out to up to 15 drives. So
in theory a single cable between machine and drive enclosure could
connect up to 60 drives!

For an application where you don't need simultaneous access to all the
drives (eg. streaming at most a few Movies), there's more than enough
bandwidth in a SATAII link to share the link between multiple drives.

A 25 drive version is possible off the shelf using a combination of these:

http://www.cooldrives.com/rasaii3g4plo.html
http://www.cooldrives.com/sapciadsaian.html
(or http://www.cooldrives.com/cosamuhoad4x.html)
http://www.cooldrives.com/seatamcasaii1.html
http://www.cooldrives.com/musaenscopde.html
http://www.cooldrives.com/cosapomubrso.html

Jim