Hardware Reference
In-Depth Information
Most standard motherboards require only a single four-pin +12V power
connector, which is provided by any current ATX12V power supply.
You need concern yourself with this issue only if the motherboard you
use requires additional +12V power connectors, which very few desk-
top boards do.
PCIe power connector
Most entry-level and midrange video adapters can be powered by
the PCIe slot itself, but the very fast video adapters used in some gam-
ing systems may require much more power than the PCIe slot can
provide. ATX12V 2.1 and later power supplies include one or more
PCIe power connectors to provide additional power to the video
adapter(s). These connectors plug directly into the video card, sup-
plying supplemental power beyond the power that is provided by
the PCIe slot itself.
The original PCIe power connector, defined in the ATX12 2.1 speci-
fication, is a six-pin (3
×
2) connector that must be capable of provid-
ing up to 75W of supplemental power to a video adapter. ATX12V
2.2 defined an eight-pin PCIe power connector, which is capable of
supplying another 150W to a video adapter. The eight-pin adapter
is backward-compatible with the six-pin adapter, so a video adapter
that requires a six-pin PCIe power connector can be powered by an
eight-pin PCIe power connector. The converse is not true, because a
video adapter that accepts an eight-pin PCIe power connector may
draw more current than the six-pin PCIe power connector can supply.
Current ATX12V power supplies provide at least one six-pin PCIe pow-
er connector. High-wattage power supplies may provide several PCIe
power connectors (six-pin, eight-pin, or some combination thereof ).
For example, the PC Power & Cooling TurboCool 1200, a power supply
popular among extreme gamers, provides three six-pin PCIe power
connectors and three six/eight-pin PCIe power connectors.
Other than gaming systems, very few systems require the PCIe power
connector at all, so most builders need not concern themselves with
the number or type of PCIe power connectors present on the power
supply. If you are building an extreme gaming system, pay close at-
tention to the number and type of PCIe power connectors, particu-
larly if you plan to install two or more video cards.
Peripheral power connectors
All power supplies provide some or all of the following peripheral power
connectors:
Berg power connector
Some current power supplies no longer include the obsolete four-pin
Berg power connector. This connector was used to power floppy disk
drives, which are now nearly extinct. (Of the few floppy disk drives still
available, most of them, including internal models, are USB-powered.)
