PC Hardware in a Nutshell, 3rd Edition [Electronic resources] نسخه متنی

4.6 Installing a Processor

The
following sections describe the steps required to install and
configure standard slotted and socketed processors. The steps we
describe are generally applicable to any modern processor of a given
type, but the details may vary slightly between different processors,
particularly with regard to such things as configuring the
motherboard and installing heatsink/fan units. If this is the first
time you've installed a processor, or if you are in
doubt about any step, refer to the documentation provided by the
manufacturer of your specific processor and motherboard.

Before you install any processor, make sure that you have identified
exactly both the processor itself and the motherboard you plan to
install it in. If the processor is not new, you can identify it using
the steps described earlier in this chapter. All high-quality
motherboards have information printed on the board itself that
identifies the manufacturer, model, and revision number. If the board
does not contain such information, you may be able to identify the
board by writing down the full BIOS string displayed by the BIOS boot
screen and checking that string against one of the BIOS sites listed
in Chapter 3. However, such
"anonymous" boards are generally of
very low quality, so it's usually better to replace
such a board rather than attempt to use it.

Before you install a processor, make absolutely sure the processor is compatible with the motherboard. It is not safe to assume merely because the processor fits the socket or slot that that processor will function properly in that motherboard. In some cases, the processor simply will not work. For example, there are many incompatibilities between Socket 370 processors and motherboards. Not all Socket 370 processors can be used in all Socket 370 motherboards, even if the processor and the motherboard were both made by Intel. In that situation, no damage is done. The processor simply doesn't work. There are, however, two common situations in which installing an incorrect processor may damage the processor and/or the motherboard: Installing a fast processor in a motherboard designed to use only slower versions of that processor. For example, a Slot 1 Pentium II/III motherboard may be rated to accept processors no faster than 450 MHz. Installing a 550 MHz Slot 1 Pentium III may damage the processor or motherboard because the faster processor draws more current than the VRM on the motherboard is designed to supply. Installing a processor that requires low voltage in a motherboard that can supply only higher voltage. This problem arises only with Socket 7 and earlier motherboards. Slot 1 and later motherboards and processors automatically negotiate the proper voltage. If the motherboard cannot supply the voltage required by the processor, it simply does not power the processor at all. But if you are installing a late-model Socket 7 processor in an older motherboard, be very certain that that motherboard can supply the proper lower voltages required by the new processor (and that it is configured to do so). Otherwise, your new processor may literally go up in smoke the first time you apply power.

The exact sequence of steps required
to install a processor depends on its packaging (slotted versus
socketed) and whether it comes with a heatsink and fan installed.
Regardless of processor type, always begin by laying the motherboard
flat on a firm surface, padding it with the antistatic foam or bag
supplied with it. Inserting the CPU (and memory) may require
substantial force, so it's important to ensure that
the motherboard is fully supported to avoid cracking it.

Before you install any processor, obtain and read the
installation documentation for both the processor and the
motherboard. Spending a few minutes doing that may well save you
hours of frustration.

4.6.1 Installing a Socketed Processor

All
modern mainstream processors are socketed rather than slotted. These
include the Intel Pentium III and Celeron (Socket 370), the Intel
Pentium 4 (Socket 423 and Socket 478), and the AMD Athlon and Duron
(Socket A). Fifth-generation processors such as the Intel Pentium and
AMD K5 use Socket 5 or Socket 7, and hybrid fifth/sixth-generation
processors such as the AMD K6 series and Cyrix 686 series use Socket
7.

Installing any socketed processor is a straightforward operation if
you do things by the numbers. The most important thing to remember is
that processors are particularly sensitive to static shock. Take
great care to observe antistatic procedures while you are handling
the processor. It's a good rule of thumb to always
keep one hand in contact with the PC power supply while you handle
the processor.

All recent socketed motherboards have a Zero Insertion
Force (ZIF) socket. As its name
implies, the ZIF socket allows a chip with hundreds of pins to be
seated easily. Older friction-fit sockets made it nearly impossible
to seat a complex chip with hundreds of pins properly. If you
encounter a motherboard without a ZIF socket, that in itself is a
good reason to replace the motherboard before installing the new
processor.

Regardless of the type of socketed processor you are installing, take
the following preliminary steps:

If you are installing a new processor in an older system, before you
begin work check to see if an updated BIOS is available for the
system. The new processor may require a BIOS update to function at
full capacity, or indeed to function at all. If a new BIOS is
available, download it and update your PC as described in Chapter 3.

Move the PC or motherboard to a well-lit work area, preferably one
with all-around access. Collect all of the tools, software, manuals,
and upgrade components you need. Read through the processor
documentation before proceeding.

To install a processor in a new motherboard, ground yourself, remove
the motherboard from its packaging, and place it flat on its
accompanying antistatic bag. If you are installing a new processor in
an existing PC, you can probably do so without removing the
motherboard, although you may have to reroute or temporarily
disconnect cables to gain unobstructed access to the socket.

If a heatsink and/or fan are not already installed on the processor,
check the instructions or examine the components to determine whether
the cooling devices need to be installed before or after you install
the processor in the socket. Some cooling devices are easy to install
regardless of whether the processor is already in its socket. Most
are designed to be installed with the processor already seated in its
socket, but a few are easier to install on a loose processor. If your
cooling device appears to be easy to install either way, install it
after the processor is in the socket. That makes it much easier to
get the processor aligned and seated correctly. When you install the
cooling device, don't forget to apply thermal
compound if the documentation recommends it.

4.6.1.1 Installing Socket 5 and Socket 7 processors

Socket 5 and Socket 7 motherboards must be configured properly to
support the particular processor you are installing. If you are
installing a Slot 1 or later processor, skip to the following
section. If you are installing a Socket 5 or Socket 7 processor, take
the steps described in the preceding section, and then continue as
follows:

Use the processor and motherboard documentation to verify that the
processor and motherboard are compatible, and to determine the proper
settings for bus speed, CPU multiplier, core voltage, and I/O
voltage. Use the motherboard manual or
manufacturer's web site to locate the configuration
jumpers and to determine the jumper settings that match those
required by the new processor. On some systems, settings are made by
a combination of jumper settings and entries in BIOS setup. There are
four settings you may have to make, all of which may not be present
on a given motherboard:

Bus speed





All Socket 5 and Socket 7 motherboards provide settings at least for
60 and 66 MHz. Some motherboards provide higher bus speeds, often
including 75 and 83 MHz. These higher bus speeds are used to
overclock a 60 or 66 MHz processorrunning it faster than its
rated speed. Don't use these settings unless you are
sure you want to overclock the processor. More recent Socket 7
motherboards, called Super7 motherboards, also provide 95 and 100 MHz
bus settings, which are the standard speeds for newer Socket 7
processors. These motherboards may also include various overclocking
settings, including 103, 112, and 124 MHz. Again, avoid using
overclocking unless you are making an informed decision to do so.




CPU multiplier





The product of the bus speed and CPU multiplier determines how fast
the processor runs. For example, using a 60 MHz bus speed with a 2.5X
multiplier runs the processor at 150 MHz. Note that some processors
convert the chosen CPU multiplier internally to a different
multiplier. For example, some processors convert a 1.5X CPU
multiplier motherboard setting to an internal 4.0X multiplier. Note
also that some CPUs are named with a "performance
rating" rather than their actual speed. For example,
the WinChip2-300 actually runs at 250 MHz (100 MHz x 2.5), but uses
the "300" name to indicate its
supposed performance relative to other processors. When setting the
bus speed and CPU multiplier, it is important to choose settings that
run the processor at its actual rated speed rather than the labeled
performance equivalent.

You can sometimes choose between two combinations of bus speed and
CPU multiplier that have the same product. In this case, choose the
combination of the higher bus speed and lower multiplier, so long as
the higher bus speed is supported. For example, when installing a 300
MHz processor, you can choose 66MHz/4.5X or 100MHz/3.0X. Either
setting runs the processor at 300 MHz, but the latter setting
provides marginally faster performance by allowing data to be
communicated faster between the CPU and the external L2 cache memory.




Voltage





Different processors require different voltages. Some processors
operate on a single voltage, and others (called split rail
processors) require different values for Core
Voltage and I/O Voltage. Old
motherboards may support only one fixed voltage, and so may not be
usable with recent low-voltage or dual-voltage CPUs. Pay close
attention to voltage because installing a low-voltage CPU in a
high-voltage motherboard may destroy the processor. Adapters are
available to allow installing newer low-voltage processors in older
motherboards, but in that situation it is better in every respect
simply to replace the motherboard.




Asynchronous PCI





Systems with a 60 or 66 MHz FSB run the PCI bus at half
speed30 MHz and 33 MHz, respectively. Systems with a 100 MHz
FSB run the PCI bus at one third speed33 MHz. This process of
using these fixed divisors is called synchronous PCI. But PCI devices
are unreliable much above 33 MHz, and overclocking the system by
using a 75, 83, or 95 MHz FSB would cause the PCI bus to run at 37.5
MHz (marginal), 41.5 MHz (unusable), or 47.5 MHz (ridiculous). So
many motherboards designed to support overclocking include a jumper
that allows setting the PCI bus to 33 MHz regardless of the FSB
speed.




Once you have set and verified all jumpers, lift the ZIF lever, which
is located on one side of the socket, as far as it will go. If there
is a processor in the socket, grasp it firmly and lift it free. It
should come away without resistance.

Locate Pin 1 on the new processor. Pin 1 is usually indicated by a
dot or beveled edge on one corner of the processor, or by a missing
pin on that corner. Locate Pin 1 on the ZIF socket, which is usually
indicated by a dot or beveled edge, and sometimes by a numeral 1
silk-screened onto the motherboard itself. Orient Pin 1 on the new
processor to Pin 1 on the socket and then gently press the processor
into the socket, as shown in Figure 4-14. The
processor should seat fully with little or no resistance, dropping
into place because of its own weight. If the processor does not seat
easily, remove it, verify that the pins align correctly, and try to
seat it again. Avoid excessive force when seating the processor.
It's easy to bend pins, and straightening them is
next to impossible.




Figure 4-14. Dropping the processor into the socket, where it should seat fully by its own weight (Be sure to align the pins first)




The processor shown in Figure 4-14 is an Intel Pentium/200, which we were relocating from a system with a failed motherboard to replace a slower processor in another system. The mottling visible on the processor is the remnants of the thermal pad from the old heatsink. Good practice would have been to clean the leftover parts of the thermal pad from the processor and heatsink before proceeding, but we simply added a dollop of thermal goop, which worked fine. We certainly wouldn't do this on any processor we cared about.

Once the
processor is fully seated, press the ZIF lever down until it is
parallel to the edge of the socket, as shown in Figure 4-15. This locks the processor into the socket and
makes electrical contact on all pins.

Figure 4-15. The ZIF
lever pressed down and locked into place




If you did not previously install the cooling device, do so
now. Don't forget to use thermal compound to improve
heat transfer between the processor and the cooling device. Most
heatsinks and heatsink/fan units clip directly to the processor or to
the socket. Once you have the heatsink aligned properly with the
processor (most fit properly in only one orientation) align the clip
and press down until it locks into place, as shown in Figure 4-16. If your cooling unit includes a fan, attach
the fan power cable to a motherboard fan power header or to an
available power supply connector, as appropriate.

If no thermal compound or pad was supplied with the heatsink/fan, buy a tube of thermal goop at Radio Shack (it costs $2 or so) and use it. A processor installed without thermal compound may run 20C or more hotter than one with thermal compound, which at best may shorten the life of the processor and at worst may cause frequent system hangs or physical damage to the processor. Thermal compound is frequently omitted, sometimes even on name-brand commercial PCs, so it's worth checking any processor that you didn't install yourself. If you are installing a recent AMD processor, pay close attention to AMD's published requirements for cooling. Using anything other than a brand of phase-change media specifically approved by AMD may void your warranty.

Figure 4-16. Attaching the heatsink securely using the locking clips




If you are upgrading to a faster processor, do not assume that you can use the heatsink/fan unit from the original processor. Faster processors may generate more heat, and may require a more capable HSF unit. Running a newer, hotter processor with the old HSF may at best result in sporadic lockups and at worst in damaging the processor. We said this earlier in the chapter, but it bears repeating.

Install the motherboard, if necessary,
connect or reroute any cables you moved, do a quick visual once-over,
reconnect the monitor, keyboard, and mouse, and then apply power to
the system. The system should begin a normal boot sequence. If
nothing (or something strange) happens, immediately turn the power
off and reverify all connections and settings.

Once the system boots normally, enter
CMOS Setup and make whatever changes, if any, the processor
documentation recommends. Once the system is working normally, turn
off the power, reinstall the chassis cover, return the PC to its
working location, reconnect all cables, and restart the system.

4.6.1.2 Installing modern socketed processors

Installing recent socketed processorsthe Intel Pentium
III/4/Celeron or the AMD Athlon/Duronrequires essentially the
same steps described in the preceding section, except that recent
processors do not require the motherboard be configured manually.

Most Socket 370, Socket 423, Socket 478, and Socket A motherboards are self-configuring. They detect the type and speed of processor installed and properly configure FSB speed, CPU multiplier, voltage, and other settings automatically. However, some motherboards intended for overclockers allow overriding information supplied by the processorfor example, by setting a 66 MHz FSB Celeron to run at 100 MHz FSB. Depending on the motherboard, changing such settings may require setting jumpers or altering the default BIOS settings. All such motherboards we have seen default to "Auto," which uses the settings supplied by the processor.

There are, however, several issues
to be aware of when installing a modern socketed processor:

As we explained in some detail earlier in this chapter, compatibility
between motherboard and processor is a major issue. That a processor
physically fits the motherboard socket is no guarantee that it will
work at all, or even that attempting to use it will not damage the
processor and/or motherboard.

With Socket A, AMD has done a much better job of maintaining forward-
and backward-compatibility than Intel has done with Socket 370. Even
so, with either AMD or Intel processors, it's
important to check that the motherboard supports the exact processor
you plan to install.

In particular, make sure that the motherboard is rated for processors
at least as fast as the processor you plan to install. If the
motherboard documentation mentions only slower processors,
don't give up hope. High-quality motherboards are
often over engineered, using larger VRMs than necessary to support
the processors they were designed for. It's quite
possible that the motherboard maker issued updated specifications for
your motherboard that include support for faster processors. Check
the motherboard manufacturer's web site to make
sure.

Also verify that the motherboard supports the FSB speed of the
processor. If it doesn't, the processor will still
operate, but at a much reduced speed. For example, installing a 133
MHz FSB Pentium III/933 in a motherboard that supports only a 100 MHz
FSB causes that processor to run at only 700 MHz. Similarly,
installing a 266 MHz FSB Athlon in a motherboard that supports only
the 200 MHz FSB means that processor runs at only 75% of its rated
speed.

The BIOS revision level can determine which processors your
motherboard supports. A later BIOS may add support for faster
versions of a given processor, and may also add support for an
entirely new processor. For example, we have an early Slot 1 board
that was designed for the cacheless Slot 1 Celeron and did not
support later Slot 1 Celerons, which included embedded L2 cache. A
BIOS update for that board added support for cached Celerons, and a
subsequent BIOS update added support for the new features and changed
caching scheme of the Pentium III. Don't assume that
because you just purchased a motherboard that it necessarily has the
latest BIOS. Some makers, notably Intel, issue BIOS revisions very
frequently, and the motherboard you receive may have been in the
pipeline for weeks or even months. Before you install a processor in
any motherboard, new or old, the first thing you should do is
identify the motherboard precisely, check the
manufacturer's web site for the most recent BIOS
update, and download that update. Once you have the system up and
running, install the updated BIOS before you do anything else.

A motherboard with an early BIOS revision may create a "can't get there from here" situation. That is, the processor you want to install may refuse to boot without a later BIOS revision than is currently installed on the motherboard. In that case, the best alternative is to install temporarily a processor that the earlier BIOS supports. That's why when we upgrade older systems, we install the latest BIOS version on the old system before we remove the original processor. That's also why we keep a stack of old processors around.

Many motherboard manufacturers, including top-notch ones such as
Intel, have a nasty habit of slipstreaming revisions. Even two
motherboards with identical model numbers may be significantly
different. In some cases, that difference is as trivial as different
BIOS versions, which is easily fixed. Other times, though, there are
very real hardware differences between the boards, and those
differences may determine which processors a particular board
supports. For example, Intel has produced the popular D815EEA2
"Easton 2" motherboard in two
distinct forms. Both versions use the 815E chipset, but the version
with an early chipset revision level does not support Tualatin-core
Pentium III and Celeron processors. If you have the earlier version,
you're out of luck. The newer processors simply
won't run in it.

If you're buying a new motherboard, check the
manufacturer's web site to determine the current rev
level and ask the vendor whether the motherboard he wants to sell you
is the latest rev level. If not, buy your motherboard elsewhere. If
you're using an older motherboard, check the
manufacturer's web site to determine what variants
exist and what implication those variants have for processor support.

Socket 370 processors are a particular problem in this respect. There
are three different physical forms of Socket 370 processors you are
likely to encounter. Early Socket 370 processors use PPGA packaging.
These processors have a flat top, with the processor chip itself on
the bottom (pin) side of the package. Pentium III and Celeron FC-PGA
processors also have a flat top, but with the processor chip
protruding above the surface of the processor, on the side opposite
the pins, where it comes into direct contact with the heatsink. The
most recent Pentium III and Celeron processors use FC-PGA2 packaging,
which is similar to FC-PGA but includes a flat metal integrated heat
spreader that shrouds the processor chip itself.

Each of these styles requires a physically different heatsink. Using
an incorrect heatsink may damage the processor, either physically or
by allowing it to overheat. For example, clamping a PPGA heatsink
(which has a flat contact surface) onto an FC-PGA processor (which
has a raised processor chip) may literally crush the processor.
Conversely, installing an FC-PGA heatsink on a PPGA processor may
allow the processor to overheat because a portion of it is not in
contact with the heatsink.

Heatsink rating is another issue. Faster processors generate more
heat, and require larger or more efficient heatsinks.
Don't assume that just because a heatsink is
designed to be used with a particular type of processor it is usable
with that processor running at any arbitrary speed. For example, a
particular heatsink may be designed to cool an AMD Duron running at
850 MHz or less. Using that heatsink on a 1.2 GHz Duron will likely
allow the processor to overheat and perhaps damage itself.

Don't assume that all heatsink/fan units will necessarily fit your motherboard and case. Some heatsink/fan units are physically quite large and may not fit. In particular, the portion of the heatsink that overhangs the processor may come into contact with capacitors and other components that protrude above the motherboard. It's not uncommon to find that clamping the heatsink/fan unit into place crushes components that immediately surround the processor socket, so be very careful. Some case/motherboard combinations are also incompatible with some heatsink/fan units because the heatsink/fan is so tall that it cannot be installed because the power supply or portions of the chassis block the space needed by the heatsink fan. If in doubt, measure the available clearances before you order a heatsink/fan unit, and make sure you can return a unit that is incompatible with your motherboard and/or case.

Whichever processor you install, make absolutely
certain that the heatsink you plan to use both fits that processor
properly and is rated for the processor speed. If you buy a
retail-boxed processor, it will come with a heatsink/fan unit
appropriate for the processor. If you buy an OEM processor or are
reinstalling a processor pulled from another system, make sure the
heatsink you use is rated for that particular processor.

Most people don't think about the power supply when
they're building or upgrading a system, but the
power supply can be a critical issue. Many systems, particularly
mass-market systems and consumer-grade systems from major OEMs such
as Gateway and Dell, have power supplies that are marginal at best,
both in terms of quality and output rating. For example, we have a
full-tower Gateway system that arrived with a 150W power supply, and
that's

after we paid for an
upgraded power supply. How small must the standard power supply have
been?

Modern fast processors have high current draws, and you cannot safely
assume that the existing power supply has enough reserve capacity to
power them adequately. If you're building a system
or upgrading the processor speed significantly in an existing system,
make sure that your power supply is up to the job. Otherwise, you may
find that the system will not even boot. If the power supply is
barely adequate, you may find that the system crashes frequently. We
often hear from people who've upgraded their systems
with first-rate motherboards and processors, only to find that the
new system crashes at the drop of a hat. When that happens, it
usually turns out that they've used generic memory
or that they just assumed the original power supply would be good
enough. Often, it wasn't.

4.6.2 Installing a Slotted Processor

Although
mainstream slotted processors are now obsolescent, they remain in
limited distribution. A faster slotted processor may be a worthwhile
upgrade for an older system. Installing a faster slotted processor
can greatly improve system performance and extend the useful life of
an otherwise obsolescent system.

For example, until late 2001 our Internet gateway system was an older Celeron. We'd been having some problems with it locking up, which we suspected were caused by the commodity memory installed in it or by the undersized power supply. One day, after three lockups in as many hours, Robert (who is a procrastinator) finally decided to do something about it. We tore down that system and replaced the power supply with an Antec unit and the 64 MB of generic memory with a 128 MB Crucial stick. While we had the case open for a cleaning and general upgrading, we noticed that the system still had its original Celeron/333 installed, so we decided to replace it with a Pentium II/450 that we'd pulled from another system. The faster clock speed and larger L2 cache of the Pentium II yield performance nearly twice that of the original processor, which takes that system from marginal to more than sufficient for the gateway and mail server tasks to which it is devoted. For a cost of less than $100 (even if we'd had to buy the processor), we now have a reliable Internet gateway system that we expect to continue using for several years to come.

Installing a slotted processor is in some ways easier than
installing a socketed processor and in some ways harder. Intel
manufactures processors for two similar but incompatible slots. The
242-pin connector, formerly called Slot 1, accepts slotted Celeron,
Pentium II, and Pentium III processors. The 330-pin connector,
formerly called Slot 2, accepts Pentium II/III Xeon-class processors.
These various processors come in different physical packaging (SEC,
SEC2, SEPP, etc.), each of which uses a different retention
mechanism. For example, an SEC Pentium II and an SEPP
Celeron both fit the same Slot 1, but use different and incompatible
retention mechanisms.

To further complicate matters,
Intel ships the same processor in different variants. For example,
the retail-boxed version of the Pentium II processor comes with an
attached fan, while the OEM version of that processor does not. If
you purchase an OEM processor with an attached fan, that package may
or may not fit the standard retention mechanism (although it usually
does fit). So, the first rule is to make sure that the retention
mechanism accepts the processor. If you purchase a cooling device
that does not fit the standard retention mechanism, it should be
supplied with a mechanism that fits it. Thankfully, all retention
mechanisms mount to the standard set of holes in Slot 1 motherboards.
Fortunately, AMD Slot A processors are a much simpler matter. All of
them use the same physical mounting mechanism, and all Slot A
motherboards can accept any Slot A processor. To install a Slot 1
Intel Celeron/Pentium II/Pentium III or a Slot A AMD Athlon
processor, take the following steps:

When installing a new processor in an older system, determine
if a BIOS update is available because the processor may require a
later BIOS to support its new features. For example, the Intel
SE440BX2-V motherboard accepts various Slot 1 processors, including
some Pentium IIIs. But you must upgrade the BIOS to take advantage of
the new Pentium III SIMD instructions. Installing the Pentium III
without upgrading the BIOS simply makes the Pentium III run like a
faster Pentium II. If a new BIOS is available, download it and update
your PC as described in the preceding chapter.

Move the PC or motherboard to a well-lit
work area, preferably one with all-around access. Collect all of the
tools, software, manuals, and upgrade components you need. Read
through the processor documentation before proceeding.

To install a processor in a new
motherboard, ground yourself, remove the motherboard from its
packaging, and place it flat on its accompanying antistatic bag. If
you are installing a new processor in an existing PC that uses a
compatible retention mechanism, you can probably do so without
removing the motherboard, although you may have to reroute or
disconnect cables to gain unobstructed access to the slot. If the
retention mechanism needs to be replacede.g., when upgrading a
Celeron system to a Pentium IIIyou may or may not have to
remove the system board to replace the retention mechanism.

If it is not already installed, install
the retention mechanism by following the instructions supplied with
it or with the motherboard. Standard retention mechanisms are notched
at one end to match the notch in the Slot 1 connector on the
motherboard. Align the retention mechanism and seat the four posts
into the matching holes on the motherboard. Press down firmly until
the retention mechanism seats. Each post has a sliding internal pin
topped by a flat, circular piece of white plastic. Forcing that pin
down into the post expands the bottom of the post on the far side of
the motherboard, securing the post to the motherboard. Press down
each of the pins until it snaps into place. Some newer Slot 1
motherboards come with the retention mechanism already installed, but
with the vertical supports folded flat. If your motherboard is like
this, lift the vertical supports until they snap into place.

If the cooling device is not already
installed on the processor, install it now. Some processor packages
also contain a supplementary support mechanism designed to secure the
processor against the additional weight and vibration of the cooling
fan. If your package contains such a supplemental support, install it
on the processor according to the instructions provided with it.

Refer to the processor
documentation to determine the proper settings for bus speed and CPU
multiplier. Refer to the motherboard manual or manufacturer web site
to locate configuration jumpers and to determine the jumper settings
that match those required by the new processor. Some boards have
separate jumpers for FSB speed and CPU multiplier, others have
jumpers for CPU speed only (which implicitly sets both FSB speed and
CPU multiplier), and still others use "jumperless
setup" which sets FSB and CPU multiplier options in
CMOS Setup. Slot 1 processors do not require voltages to be set
manually. All current Slot 1 processors use 3.3 volts for external
I/O. Klamath-based processors use 2.8 volts internally, and
Deschutes-based processors use 2.0 volts. Voltage setting is handled
completely automatically via the Voltage ID (VID) pins on the
processor itself.

Once you have
made necessary jumper changes, if any, install the processor, first
removing the existing processor if necessary. Note that the card-edge
connector on the processor has a key notch, as does the slot. Slide
the processor into the support bracket, making sure that the key is
oriented properly, as shown in Figure 4-17.

Figure 4-17. Guiding the
processor into place, while aligning the keying tab in the slot with
that in the processor's card-edge connector




Using both thumbs, press down firmly on
the processor until it seats fully, as shown in Figure 4-18. This may require applying significant
pressure, but you should feel and hear the processor seat. Most
support brackets have locking tabs at the top that will snap into
place to secure the processor once it is fully seated.

Figure 4-18. Using both
thumbs to press firmly until the processor seats fully




If the fan power lead is designed to
connect to a motherboard power header, connect it now. If the fan
power lead instead is designed to connect to a power supply power
connector, you'll make that connection after the
motherboard is installed in the case.

4.6.3 Completing the Installation

Once you have physically installed the processor and memory (as
described in Chapter 5), installed the motherboard
in the case, and connected all cables, you're ready
to test the system. Verify that everything is connected properly and
that you haven't left any tools in the patient.
Connect a monitor, keyboard, and mouse to the system. With the case
cover still off, apply power. Everything should spin up properly,
including the processor fan if one is installed. If it
doesn't, immediately turn the power off and recheck
your work.

Once the processor is functioning, restart the system, enter BIOS
Setup, and set the processor speed if necessary. Setting processor
speed is unnecessary with modern processors. In fact,
it's usually impossible to do so because the
processor reports its speed to the motherboard, which automatically
configures itself for that speed. Older processors may or may not
require setting processor speed manually, depending on the particular
processor and motherboard. Note that with some motherboards, you must
move a jumper from "Normal" to
"Configure" mode before you can
change some settings, including processor speed. Once you have
configured BIOS settings appropriately, save the changes and turn off
the system.