1 x 4-pin ATX 12V Power connector = ....?

MachineMessiah wrote:
> a 4 pin cpu power connector on the motherboard?
> I need a new motherboard but my 550 watt power supply doesn't come with
> an 8 pin connector for the cpu. If the board was 8 pin would the specs
> say 2 x 4 pin?

If the board has a 2x4 (8 pin connector), it is prepared for high power
consumption processors. A 2x2 connector, has two 12V wires, and if you
allowed them to carry 6 amps each, that would be 12 amps of capacity.
12V * 12A = 144W. (They are probably capable of a bit more than that,
and the 6 amp number is conservative. I'd have to find the connector
datasheet again, to verify the real number.) If the 144W of power is
converted by a Vcore regulator at 90% efficiency, that is 129.6W of power
that the processor can use. Rounding off, that is 130W, which is enough
for a high end P4 processor from a previous era.

The whole 8 pins are useful, if you were doing an overclocking experiment,
and were expecting a lot more power than that to flow. Overclocking a
Pentium D 805 to 4GHz, would be an example where a motherboard with a
2x4, and a power supply with a 2x4 connector, might be useful. The power
consumed there, is over 200W.

Many of the processors people are using now (Core2 Duo or some of the
AMD socket AM2 processors), use less power than the 130W number. The
Core2 Duo is 65W, or half that. As a result, you can use a 2x2 PSU
power connector, on a 2x4 equipped desktop board, without too much
danger of the connector melting or anything. For most people, there
is nothing to worry about. Only the "rocket scientists" are in
danger of melting something (the D 805 people who try to get the
same results as the Tomshardware overclocking article).

HTH,
Paul