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Motherboard Configuration Procedure
This procedure describes the steps required to configure a motherboard for installation. You will normally
use this procedure when building a new PC or performing a motherboard upgrade. Configuring
the motherboard is traditionally done using jumpers, which are small pieces of
plastic and metal that are used to change how the circuitry on the motherboard functions.
Some newer boards today are called jumperless, because they use not jumpers but
rather a special group of BIOS settings to
set most of the configuration options that are set with jumpers on conventional boards
(they do still have some jumpers so the name isn't entirely accurate). These
boards reduce this particular procedure a great deal (but add an additional step later on
in the build process). You still need to look through this procedure however since as I
say, these boards do have some jumpers.
Note that this procedure covers configuration only; installation is addressed in this procedure.
- Difficulty Level: 3 (Moderate). Motherboards can be quite confusing to
figure out and it can be hard to find where all the jumpers are.
- Risk Factor: 4 (High). Setting the incorrect jumpers on the motherboard
can lead to permanent hardware damage or data loss. If you are careful this won't happen
but it is a possibility.
- Hardware Required: Needle-nose pliers, or another tool for grasping
small objects (jumpers are very small). Long fingernails will do for some people.
- Software Required: None.
- Time to Perform: 10-15 minutes, as long as you know what the jumper
settings need to be or your manual contains the necessary information.
- Preparation / Warnings:
- If you have not already done so, please read the section on general
installation and assembly tips.
- This procedure lists the most common jumper settings, and is not an exhaustive list.
Always set and/or check every jumper that your board has. Similarly, some of the settings
discussed here may not apply to your particular board.
- Some motherboards aggregate two or more of the individual jumper settings listed in this
procedure into a "processor type" group setting that changes several functions
at once. For example, some boards instead of spelling out the jumper settings for
processor core voltage, I/O voltage, system bus speed and multiplier, just list every one
of the common CPUs and tell you how to set a block of different jumpers. Some manuals
actually show it both ways. It doesn't really make much difference, although you should
realize that if the individual jumpers are not listed, and you are using a newer CPU that
wasn't around when the manual was printed, you will have to contact the manufacturer to
find out what the jumper settings are for it. This procedure shows only the individual
- Always check all the jumper settings. Many motherboards have some jumper settings that
are almost never changed from their defaults. Do not be lulled into not checking these, as
sometimes the manufacturer will not correctly set defaults. Incorrect jumper settings can
cause bizarre problems later on that are very hard to trace back to their actual cause.
- Similarly, some vendors will considerately pre-jumper the board to match the CPU and
other hardware you are using, if you buy this other material with the motherboard. This is
a nice service, but you should still double-check the settings. Vendors are human too, and
it's your hardware.
- Jumpers are most often labeled with a "JP" prefix, such as "JP20",
however many boards label them differently. Watch out for boards that use "JP"
for jumpers" and "J" for pin connectors (such as the hard disk LED,
speaker, etc.) It can be easy to mix up "J16" and "JP16". I've seen
boards that even mixed "J" and "JP" for both jumpers and connectors!
I'd like to smack some of these designers around sometimes. :^)
- Be careful to jumper the processor based on the true bus speed and multiplier settings
required for it, and do not be fooled by the "P"
rating on some CPUs. For example, the Cyrix 6x86L-PR166 runs at 133 MHz, not 166. See
the reference section on processor families if
you need to look up the specifics for any processor, but this information is normally in a
good motherboard manual.
- Some newer CPUs interpret multiplier settings differently from what they are specified
as in the motherboard manual. In particular, since most standard Pentium motherboards do
not have a 3.5x multiplier, processors like the K6-233 interpret 1.5x as 3.5x, and should
be jumpered using the 1.5x setting.
- If necessary, first carefully unpack the motherboard from its packaging and inspect it
- Always exercise care in the handling of the motherboard. Watch out for ESD. I normally place the motherboard on top of the
anti-static bag in which it came while working on it, and then on top of something soft to
cushion the metal pins that stick through the bottom of the board. Do not put the board
directly on a work surface or you could damage the bottom of the board. Always work on a
- RTFM: This of course stands for "Read The Fine
Manual". (Now, now, none of that please, this is a "G-rated" site. :^) )
Trying to configure a motherboard without having the manual around is an exercise in
masochism. If you don't have the manual, find it, ask your vendor or local shop if they
have a spare, or try to see if you can find jumpering information from the manufacturer or
on the Internet. Assuming you do have the manual, read the section that describes the
jumpers on your particular board. You will want to set or check every one of these
jumpers. Also look at the picture of the board included in most decent manuals, to
physically locate where the jumpers are.
- Set Processor Voltage Jumper(s): Most newer motherboards will have two
voltage specifications, one for the internal (core) voltage of the CPU, and one for the
external (I/O) voltage. See here for details
on these voltage levels. Be sure to set the correct levels for your CPU; again,
the manual may tell you what settings you need for the processors it supports. If you are
using an older processor without split-rail voltage, set both settings the same
- Set Processor Speed Jumpers: The speed of the processor is determined
by two primary jumper settings: the system bus speed, and the multiplier (how many times
the bus speed the CPU speed is). For example, a Pentium with MMX 200 uses a system bus
speed of 66 MHz and a multiplier of 3x. Watch out for newer CPUs that use a lower
multiplier which is interpreted differently by the CPU. For example, 233 MHz processors
are often jumpered as 66x1.5, and the CPU interprets the 1.5x as 3.5x internally. Again,
consult your manual.
- Set Secondary Cache Size and Type Jumper: Some motherboards accept
cache in different configurations and therefore have jumpers depending on how much cache
is on the board and whether it is soldered on or inserted via a COASt module. Some boards, especially
those using the Intel 430HX chipset,
may have a jumper that needs to be set if you have inserted a second tag RAM chip to
enable caching over 64 MB of system memory. Increasingly, newer boards are doing away with
these different configurations so this jumper is becoming less common. You definitely
won't find anything like this on a Pentium Pro or Pentium II motherboard, since these
processors have their own integrated secondary cache.
- Check Flash BIOS Jumper: If your system has a jumper to enable the flash BIOS feature, check it to make sure
that it is disabled. This should be the default.
- Check CMOS Clear Jumper: Some systems have a jumper that will let you
clear the contents of the CMOS memory, something that is needed most often when a system
password is set and then forgotten. Make sure that this jumper is set to the normal or
default position, or you won't be able to set any BIOS settings.
- Check Battery Source Jumper: Some motherboards use a jumper to
determine if the onboard battery is to power the CMOS memory, or an external battery.
Again, make sure this is set to the default position (onboard battery) unless using an
- Check Disable Jumpers: Some motherboards have special jumpers to allow
you to enable or disable parts of the motherboard at a hardware level (for example, the
serial/parallel ports or the floppy disk controller). Make sure that these jumpers are set
properly (normally, you won't want to disable any of these items).
- Set Memory Size Jumpers: Very rarely seen on new boards, jumpers to set
the size of the system memory were common on 486-class boards. Set these if your board
- Double-Check Settings: It may seem redundant to make all the settings
and then check them, but it's worth a few minutes to do this. Incorrectly-jumpered
motherboards are a leading cause of system problems and can be very hard to diagnose.
and Case Connection Procedure
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