"Arfa Daily" wrote in
news:O24eo.36157$r24.2988@hurricane:

Thanks for the insights Jeff. All interesting stuff. These are
dedicated games machines, not based on a PC in any way. The power
supply is specced to deliver 12v at 23 amps, yes, that's twenty
three amps ...

Almost all of this is potentially going into these two processors,
so not far off 300 watts between them. No mean task shifting the
heat off them !

Arfa



what processors(microprocessors?) run at 12V?
ISTR that today's uPs run mostly on 3.3V

Most other digital logic runs at 5V,I believe.

I think you wil find that most of your power is going into the video
drive (or LCD backlight) circuitry.

--
Jim Yanik


Er no. There are no backlights. Or display processor. These are X-Box
/ Playstation type boxes. Apart from some support circuitry in IC form
- which admittedly does gobble enough power to make it run hot enough
that a degree of heatsinking to the pcb shielding via thermal pads is
required - everything goes on in a pair of very large BGA processors,
one of which is the data processing engine, and the other of which is
the graphics processing engine. It is they which make use of the 12v,
and they which gobble the amps from it ...

The power supply does have other outputs, but these are all at very
low current availabilities, so will be for support logic and maybe
some core supplies for the two processors. Trust me when I say that
the two big chips is where all the power is going, and generating heat
that needs shifting
:-)

Arfa



Odd that BGA processors are using 12V instead of logic level voltages.

I'm surprised they don't use some sort of liquid or heat-pipe plumbing to
remove all that heat. Wasn't it the CRAYs that used liquid Freon to flood
the processor cabinet to dissipate al the heat built up?

--
Jim Yanik
jyanik
at
localnet
dot com