[mythtv-users] external power supply rant (Was: Zotac ION M/B..)
Simon Hobson
linux at thehobsons.co.uk
Wed May 13 18:06:59 UTC 2009
Gabe Rubin wrote:
>Why the desire for integrated power supply? Seems to me that a brick
>outside the box will reduce the need for cooling and also keep the
>case even smaller. What am I missing?
External bricks are a nuisance IMO. It's "yet another" box, and "yet
another" cable - far neater to just take the mains directly into the
unit. The power brick still needs cooling, so instead of one box, you
now have two boxes to ensure have enough airflow.
Even worse than "bump in the wire" bricks are "wall wart" bricks -
they are invariably too big to fit side by side in multi-way
extensions, they are a pain if you use a UPS as you need an extension
plugged into the UPS to get the right sockets, and of course, if you
import any equipment, it comes with the wrong sort of plug built into
the brick. Note for our US readers, the rest of the world doesn't use
the same 10A (or is it 15A) flat pronged plug that you do ;-)
From the efficiency point of view, it means that ALL power
consumption goes through two conversions instead of one. OK, there is
still the step down for the CPU supply, but 5V and 12V loads will
come directly from the PSU and have just one conversion.
If building a system, you have a large choice of mini-ATX PSUs - so
if you are going to build a box with several power hungry drives and
a tuner, you can use a larger PSU; if you are using just one drive
(or even diskless) and no tuner, then you can choose a smaller supply.
And in the comments to one of the pages linked to, more than one
person commented about using one of these (or at least one of these
ION boards coming out) as a car computer. Well in mini-ATX you can
get PSUs designed specifically for in-vehicle use - they can monitor
battery voltage and ignition status, and automatically power up/down
the system. You CANNOT do that with a single rail PSU with no other
connection to the board.
--
Simon Hobson
Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.
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