Larry Stone wrote:
I have an 8800GTX and plan to add another. How critical is the power supply.
What happens if the PS is insufficient? The certified PS's at slizone all
cost at least $150.



Well, the question would be, how well behaved is your brand of power
supply, when it overheats ? Does it just cleanly shut off ?

The more you spend for a supply, the better the chances are that
it has a few safety features. There are some older prebuilt computers,
where when the provided supply failed, it virtually guaranteed killing the
motherboard it is connected to. With more modern power supplies,
that should be less of a concern. As long as we aren't dealing with a
$25 power supply.

Considering the amount of power that will be used by the two video cards
(24 amps for two cards, 6 amps for a cheaper Core2, from +12V), one
thing a more expensive power supply can give you, is more efficient
operation. Some of the new supplies are "80%+" efficient. Which means,
when you are gaming and drawing 12V @ 30A, the supply does not get
as hot internally, and the PSU fan doesn't have to spin as fast.
The efficiency means you save a bit of electricity. The expensive supply
may also have a working over-temperature, overcurrent, and overvoltage,
and perhaps in the event of a failure (as all power supplies can fail),
the rest of your system may be well protected. I don't see a downside
to spending $150+, seeing as you have $1000 tied up in two video cards.

HTH,
Paul