Intel desktop CPU sockets and slots
Socket or slot Description
Slot 1 242-pin 2.8V and 3.3V connector for
Pentium IIs, IIIs, and Celerons
Slot 2 330-pin 1.5V to 3.5V connector for
Pentium II and III Xeons
Socket 423 423-pin 1.7V and 1.75V for
Pentium 4s
Socket 478 478-pin 1.7V and 1.75V for
Pentium 4s and Celerons
Socket 603 603-pin 1.5V and 1.7V for
Pentium 4 Xeons, and Xeon MPs
Socket 604 604-pin for Pentium 4 Xeons
Socket 611 611-pin 3.3V for Itanium 2s
Socket 755 755-pin for Pentium 4s and Celerons
Socket 775 775-pin for Pentium 4s,
Celerons, Core 2 Duo, Core 2 Extreme, and Core 2 Quads
Socket B or Socket 1366 1366-pin for Core
i7s
Table 2.7
AMD desktop CPU sockets and slots
Socket or slot Description
Socket A or 462-pin 1.1V to 1.85V for Duron
and Athlons
Socket 462
Socket AM2 940-pin for Athlon, Athlon X2,
and Semprons
Socket AM2+ 940-pin for Athlon X2, Phenom
X3, and Phenom X4s
Socket AM3 940-pin for Phenom II X3 and
Phenom II X4s
Socket 754 754-pin for Athlon and Semprons
Socket 939 939-pin for Athlon and Athlon
X2s
1207-pin
ATX power supply connectors
Connector Notes Voltage(s)
24-pin Main ATX power connector to the
motherboard +3.3, +5, +12, –12
20-pin Main power connector to the
motherboard +3.3, +5, –5, +12, –12
15-pin SATA connector +3, +5, +12
8-pin 12V for CPU +12V
6-pin PCIe video; connects to PCI video
adapter +12V
6-pin Sometimes labeled as AUX; connects to
the motherboard +3.3, +5
if it has a connector
4-pin Molex Connects to peripheral devices
such as hard drives and +5, +12
CD/DVD drives
4-pin Berg Connects to peripheral devices
such as the floppy drive +5, +12
4-pin Sometimes labeled as AUX or 12V;
connects to the +12V
motherboard for CPU
3-pin Used to monitor fan speed N/A
Figure 4.8 shows a few ATX power supply
connectors.
Figure 4.9 shows the ATX power supply
connectors. Figure
4.10 (on page 116) illustrates the
compatibility between the
two ATX motherboard connector standards.
Notice in
Figure 4.10 how the power cable is only one
connector,
notched so the cable inserts into it one
way only. This is a
Not all 24-pin motherboard connectors
much better design than older power
supplies where two
accept 20-pin power supply connectors
connectors were used that could be
reversed. Also, notice
You can purchase a 24-pin to 20-pin power
adapter.
that a power good signal (labeled PWR_OK in
the figure)
A Web site containing information regarding
power
goes to the motherboard. When the computer
is turned on,
supply form factors is
http://www.formfactors.org.
part of POST is to allow the power supply
to run a test on
each of the voltage levels. The voltage
levels must be cor-
rect before any other devices are tested
and allowed to initialize. If the power is OK, a power good sig-
nal is sent to the motherboard. If the
power good signal is not sent from the power supply, a timer
chip on the motherboard resets the CPU.
Once a power good signal is sent, the CPU begins executing
software from the BIOS. Figure 4.10 also
shows the +5vsb connection to provide standby power for
features such as Wake on LAN or Wake on
Ring (covered later in the chapter).
Tech
Tip
Power Supply Form Factors
4-pin CPU power connector
Figure 4.8
SATA power connector
115
6-pin PCIe power connector
ATX power supply
PCIe power
connector: 6-pin
Fan speed
monitor connector
4-pin floppy
power connector
Figure 4.9
4-pin Molex
power connector
Main power
connector: 24-pin
4
ATX power supply connectors
Tech
Tip
A high-quality power supply delays sending
the power good signal until all of the power sup-
ply’s voltages have a chance to stabilize.
Some cheap power supplies do not delay the power good
signal. Other cheap power supplies do not
provide the power good circuitry at all, but instead tie
five volts to the signal, sending a power
good signal even when it is not there.
The number and quantity of connectors
available on a power supply depends on the power
supply manufacturer. If a device requires a
Berg connector and the only one available is a Molex,
a Molex-to-Berg connector converter can be
purchased. If a SATA device needs a power connec-
tion, a Molex-to-SATA converter is
available. Figure 4.11 shows a Molex-to-Berg converter and a
Molex-to-SATA converter.
The power supply connectors can connect to
any
Power converters and Y connectors are
device; there is not a specific connector
for the hard
good to have in your tool kit
drive, the CD/DVD drive, and so on. If
there are not
When a service call involves adding a new
device,
enough connectors from the power supply for
the
having various power converters available
as part of
number of devices installed in the
computer, a Y power
your tool kit is smart.
connector can be purchased at a computer or
elec-
tronics store. The Y connector adapts a
single Molex
connector to two Molex connectors for two
devices. Verify that the power supply can
output enough power to handle the extra
device being installed. Figure 4.12 shows a Y power
connector.
116
ATX power supply connectors
Connector Notes Voltage(s)
24-pin Main ATX power connector to the
motherboard +3.3, +5, +12, –12
20-pin Main power connector to the
motherboard +3.3, +5, –5, +12, –12
15-pin SATA connector +3, +5, +12
8-pin 12V for CPU +12V
6-pin PCIe video; connects to PCI video
adapter +12V
6-pin Sometimes labeled as AUX; connects to
the motherboard +3.3, +5
if it has a connector
4-pin Molex Connects to peripheral devices
such as hard drives and +5, +12
CD/DVD drives
4-pin Berg Connects to peripheral devices
such as the floppy drive +5, +12
4-pin Sometimes labeled as AUX or 12V;
connects to the +12V
motherboard for CPU
3-pin Used to monitor fan speed N/A
Figure 4.8 shows a few ATX power supply
connectors.
Figure 4.9 shows the ATX power supply
connectors. Figure
4.10 (on page 116) illustrates the
compatibility between the
two ATX motherboard connector standards.
Notice in
Figure 4.10 how the power cable is only one
connector,
notched so the cable inserts into it one
way only. This is a
Not all 24-pin motherboard connectors
much better design than older power
supplies where two
accept 20-pin power supply connectors
connectors were used that could be
reversed. Also, notice
You can purchase a 24-pin to 20-pin power
adapter.
that a power good signal (labeled PWR_OK in
the figure)
A Web site containing information regarding
power
goes to the motherboard. When the computer
is turned on,
supply form factors is
http://www.formfactors.org.
part of POST is to allow the power supply
to run a test on
each of the voltage levels. The voltage
levels must be cor-
rect before any other devices are tested
and allowed to initialize. If the power is OK, a power good sig-
nal is sent to the motherboard. If the
power good signal is not sent from the power supply, a timer
chip on the motherboard resets the CPU.
Once a power good signal is sent, the CPU begins executing
software from the BIOS. Figure 4.10 also
shows the +5vsb connection to provide standby power for
features such as Wake on LAN or Wake on
Ring (covered later in the chapter).
Tech
Tip
Power Supply Form Factors
4-pin CPU power connector
Figure 4.8
SATA power connector
115
6-pin PCIe power connector
ATX power supply
PCIe power
connector: 6-pin
Fan speed
monitor connector
4-pin floppy
power connector
Figure 4.9
4-pin Molex
power connector
Main power
connector: 24-pin
4
ATX power supply connectors
Tech
Tip
A high-quality power supply delays sending
the power good signal until all of the power sup-
ply’s voltages have a chance to stabilize.
Some cheap power supplies do not delay the power good
signal. Other cheap power supplies do not
provide the power good circuitry at all, but instead tie
five volts to the signal, sending a power
good signal even when it is not there.
The number and quantity of connectors
available on a power supply depends on the power
supply manufacturer. If a device requires a
Berg connector and the only one available is a Molex,
a Molex-to-Berg connector converter can be
purchased. If a SATA device needs a power connec-
tion, a Molex-to-SATA converter is
available. Figure 4.11 shows a Molex-to-Berg converter and a
Molex-to-SATA converter.
The power supply connectors can connect to
any
Power converters and Y connectors are
device; there is not a specific connector
for the hard
good to have in your tool kit
drive, the CD/DVD drive, and so on. If
there are not
When a service call involves adding a new
device,
enough connectors from the power supply for
the
having various power converters available
as part of
number of devices installed in the
computer, a Y power
your tool kit is smart.
connector can be purchased at a computer or
elec-
tronics store. The Y connector adapts a
single Molex
connector to two Molex connectors for two
devices. Verify that the power supply can
output enough power to handle the extra
device being installed. Figure 4.12 shows a Y power
connector.
1
