Mailinglist Archive: opensuse (1777 mails)

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Re: [opensuse] Moving to IPv6
  • From: Anton Aylward <anton.aylward@xxxxxxxxxx>
  • Date: Tue, 14 Sep 2010 09:11:11 -0400
  • Message-id: <4C8F746F.20002@xxxxxxxxxx>
G T Smith said the following on 09/14/2010 07:21 AM:

I am sure someone would have said something like this about the QWERTY
keyboard layout (which was designed to slow down the typist), non-QWERTY
keyboards are still relatively uncommon in the English world.

Good illustration.
I'd add VHS in the VHS vs Beta debate.

There's _almost_ a AC vs DC issue. While Tesla may have been right in
the context that existed back then, "that was then, this is now". We
make a lot of use of DC - all our electronics runs on it, mostly low
voltage. I also have a lot of low voltage (and high efficiency) DC
lighting in my house.

By contrast, at work I have racks of equipment that _runs_ on 5V and 12V
and each unit in the rack has its own transformer and regulator to step
down from 110V (you may be use 220V) to 5V, each generating its own heat.

What is more ironic is that in the net room there is this huge UPS that
takes AC power (220V actually) and converts it to 12V. It uses that 12V
to charge batteries. The batteries then power an alternator that
converts it back up to 110V which goes to the racks. Where the units I
just mentioned convert it back down to 12V and 5V.

I can't say this makes a lot of sense to me. Surely taking that 12V
from the batteries to the racks (with some regulators etc) would make
things more efficient? Its not as the usual benefits of AC apply here,
its not as if this power is being transmitted over great distances.

History tends to show that the adoption of technology is not just about
whether it is best, but also whether the technology addresses an
important perceived need or provides a new service that there is a
demand for, the cost of adopting it, and the vested interests involved.

I realise that in the past many small communities ran on locally
generated DC. Converting them to AC and putting them on National Grid
was a matter of efficiencies of scale, reliability and management.

When I talk of running a computer room on DC, I am not talking about
giving up the efficiencies that go with AC - generation, distribution
and voltage manipulation.

The heat produces but the per-device transformers & regulators when they
step down from 110V to 5V is local to the equipment and a waste because
the low voltage is already available. Eliminating the DC-to-AC-to-DC
conversion would reduce the overall heat loading as well as the
electrical efficiency of the plant.

I just betcha someone is going to tell me that many places DO run on
per-rack DC.

Readers of the runes will tend to suspect by the time agreement is made
something new will come along.

Indeed, the Start Trek theme can continue ...

the Europe/US take up is not good. NAT made the immediate problem go
away. It yet another kludge that has become a default (as is the QWERTY
keyboard). At the moment IPv6 provides roaming internet/IP capabilities,
(something IPv4 does not do) but that is mainly of interest for
suppliers of mobile networks.

Its quite possible that two separate "worlds" might exist for a while:
the wired and the mobile.

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