When building a system from scratch, generally you should start
with a motherboard, and then select a power supply and case to
match the mobo's features and capabilities. Power supply cables
are pretty standard these days, and the biggest issue is usually
cable length, i.e. if you're going to use a full size tower make sure
the supply's cables are long enough to accomodate it.

As for the difference in PS specs, start he
http://compreviews.about.com/od/cases/a/ATX12VvATX.htm

"Erich Kohl" wrote in message t...
Hello all,

I'm a fairly serious computer enthusiast planning to assemble a new PC
from scratch within the next month or two.

I have certain cases in mind from the typical brand names (Apevia,
Cooler Master, Thermaltake, etc.), and I want to go with an aftermarket
power supply (I've learned based on people's reviews to not use the one
that is supplied with the case).

How will I know for sure that the power supply I choose will have
enough of the right types of cables to properly supply electricity to
everything on my motherboard and case that needs it (cases nowadays
seem to have a lot of extras, like temperature readouts and bright blue
LED lights)?

Also, I've seen power supplies differentiated as ATX, ATX12V, etc.
What exactly is the difference? (I at least know that ATX is the form
factor I'm going with.)

Any help would be appreciated.

Thank you.

--