Power Supplies - Upgrading and Repairing PCs - page 1079

ATX12V. The 8-pin dual +12V connector is essentially the equivalent of two 4-pin con-
nectors mated together and is used by entry-level servers to power multiple processors.
Because of the way the connectors are designed, an 8-pin +12V connector can plug into
a 4-pin +12V connector on a motherboard, with the unused pins simply hanging unused,
offset to one side or the other.
The only other major difference between EPS12V and ATX12V is that EPS power sup-
plies can be up to 180mm or 230mm deep, whereas ATX supplies are technically limited
to 140mm depth according to the specification. An example of an EPS12V type supply
from PC Power and Cooling is shown in Figure 18.7 .
Figure 18.7 EPS12V form factor power supply ( www.pcpower.com ).
Thispowersupplyisbasicallya230mm-deepEPS12Vsupplythatworksinplaceoforas
an upgrade to an ATX12V supply as long as the chassis can accommodate the additional
depth. EPS12V supplies are sometimes called extended ATX power supplies because of
theiroptionalextendedlength.IfyouplantouseoneoftheseEPS12Vpowersuppliesina
standard ATX chassis, it's important that you measure the available space in your chassis
to ensure you have the room behind the supply for the additional depth.
Connector compatibility isn't generally a problem because, by virtue of the Molex Mini-
FitJr.connectordesign,youcanpluga24-pinmainpowerconnectorintoa20-pinsocket,
as well as an 8-pin dual +12V connector into a 4-pin +12V socket.