Does
it matter which slots I plug my new module in?
In
general, you will get the best performance if you put the largest
module (in megabytes) in the lowest-numbered slot. For example,
if your computer comes with 32MB of removable memory and you
want to add 128MB, it would be best to put the 128MB module
into slot 0 and the 32MB module into slot 1.
Why
Does the Price of Memory Fluctuate?
Supply
and demand. Occasional changes in market demands will alter
inventories and, therefore, raise or lower prices.
Can
you mix and match ECC and non-parity modules?
No.
When adding new memory, you need to match what is already in
your system. You can determine if your system has parity by
simply counting the number of black memory chips on each module.
Parity and ECC memory modules have a chip count divisible by
three or five. Any chip count not divisible by three or five
indicates a non-parity memory module.
Can
DDR and SDRAM be used in the same system at the same time?
No.
Even though there are systems that support both technologies,
you can't have DDR and SDRAM in the same system at the same
time. You'll have to choose one or the other.
"Have
you ever gotten a "great deal" on a system and then been a little
disappointed with its overall performance? If so, this article
on Crucial's Web site is for you. Get the information you need
to figure out whether or not upgrading your system would be
worth the money.
What
are MultiMediaCards?
About
the size of a postage stamp, a MultiMediaCard, or MMC, is a
small, removable storage device used in a variety of electronic
devices, including digital cameras, handheld computers, and
digital music players. MultiMediaCards are designed with flash
technology, a non-volatile storage solution that does not lose
its information once power is removed from the card. MultiMediaCards
contain no moving parts and are extremely rugged, providing
users with much greater protection of their data than conventional
magnetic disk drives.
What
is CL or CAS Latency?
CL
stands for CAS Latency. It is a programmable register in the
SDRAM that sets the number of clock cycles between the issuance
of the READ command and when the data comes out. Smaller number
for CL indicates faster SDRAM within the same frequency.
Several
Memory module suppliers are offering PC133 modules with a performance
setting of 3-2-2 . What advantage does a 2-2-2 module provide?
The first number of the 2-2-2 designation refers to CAS latency,
so in short you are asking the advantage of a CAS latency of
2 over one of 3.
Adjusting
a device to CL = 2 from CL = 3 will speed up a cc ess time from
a READ command to the point at which data is available on the
data bus (1 clock quicker).
Base
on benchmark testing results, better performance improvements
were found in the 2-2-2 setting over the 3-2-2 :
Are
PC133 speed-tested SDRAMs backward compatible with PC100?
Yes. The AC timing specifications on a PC133 device are tested
to allow a system bus to run at 133 MHz.
The
PC100 and PC66 timing specifications are more relaxed on these
timings.
Majority
of PC133 chips should work at PC100 and PC66. In fact, a -75
device is specified for PC100 timings using CAS latency = 2.
Please
refer manufacturer data sheet for AC timing table in the appropriate
data sheet tCK at CL = 2.
If a SDRAM DIMM module is assembled with a -10 SDRAM chip, is
it considered PC100 compatible?
No - An SDRAM DIMM with -10 (100 MHz) chip will support only
66 MHz Systems. This type of module is not guaranteed to run
consistently in a PC100, 100 MHz system.
In
order for the module to be PC100 compatible the components need
to be marked with -8A, -8B, -8C, -8D or -8E (or 125 MHz)and
example taken from micron chips.
Micron
Modules with -8A through -8C sdram chips will run at 100 MHz
at a CAS latency of 3.
Modules
with -8D or -8E components will run at 100 MHz at a CAS latency
of 2.
Refer
to the original manufacturer data sheet to
determined the correct CAS latency setting.
What's
the difference between buffered and unbuffered DIMMs?
High density DIMMs have lots of chips on them and therefore
possess a higher capacitive load on the address and control
signals in comparison to lower density DIMMs. Some designers
use re-drive buffers on the DIMM to boost the signals to reduce
system loading when compared to the same high density module
without buffers. But,
the buffers introduce a small delay into the electrical signal,
so adding buffers to a standard density module would have the
effect of slowing down the signal, compared to the same low
density module without buffers.
What is the difference between 72 bit and 64 bit memory?
What is the difference between 32 bit and 36 bit memory?
72 bit memory is commonly known as ECC memory. It has an additional
8 bits for Error Correction Check 64 bit memory is non-ECC.
72 bit or 64 bit
configuration are typically found in 168 pin DIMMs
36
bit memory is commonly known as parity memory. It has an additional
4 bits for parity checking. 32 bit memory is non-parity. 32
bit or 36 bit configuration are typically found in 72pin or
30 pin SIMMs
Can
you tell by looking at a module if it is SDRAM, FPM, EDO etc?
SDRAM, EDO and FPM chips look similar to each other. The best
way to tell the difference is to reference the part number on
the chip. Most DRAM manufacturers have reference books or lists
on their web sites. By looking at a memory module one can attempt
to guess what it is. A general guideline is to look at the IC
type and size. The EDO and FPM chips are typically packaged
in SOJ form and are thicker when compared to that of the SDRAM
chips which are typically packaged in slim-line TSOP form. The
EDO/FPM chips typically have a marking of -60 at the end of
the string of numbers and that of the SDRAM chips typically
have markings of -12 -10 -8 -7.5. A SDRAM module typically has
a row of the resistor or resistor arrays above the contact tabs.
What is refresh rate and self refresh?
A memory module is made up of electrical cells. The refresh
process recharges these cells, which are arranged on the chips
in rows. The refresh cycle refers to the number of rows that
must be refreshed. The common refresh cycles are 2K, 4K and
8K. Refresh cycle together with refresh period determines how
often refresh is needed, which is defined as Refresh Rate. For
the same refresh period, 4K
refresh parts needs to be refreshed more frequently than 2K
parts. For the same size DRAM, 4K refresh
part consume less power than 2K refresh parts. Some specially
design DRAMs feature self refresh technology, which enables
the components to refresh on their own -- independent from the
CPU or external refresh circuits. Self refresh, which is built
into the DRAM itself, reduces power consumption, and it is commonly
used in notebook computers
What is PC SDRAM, PC100 SDRAM and Registered SDRAM?
PC SDRAM is a loose general term for SDRAM that runs at 66 MHz
and has an SPD chip for compatibility with P-II motherboards.
PC100
SDRAM refers to PC100 SDRAM chips or DIMMs that meet INTL PC100
qualification standard. These parts are designed to run at 100
Mhz front side bus (FSB) speeds.
Registered
SDRAM - This is SDRAM module with Register for Address and Control
Signals. Registered DIMMs reduce the loading of DIMM to the
motherboard so that larger capacity DIMM modules and more DIMMs
can be populated on a motherboard. It is a technique used widely
on servers to increae the amount of memory the system can support.
The Registered DIMM is a little slower in a cc ess timing versus
that of the unbuffered counterpart.
What happens if my memory is not PC-100 compliant?
It means you may experience system errors in a 100mhz system
because the memory's performance cannot keep up with the system
requirement. The system will operate at the speed of the slowest
component. For example, installing 66MHz SDRAM memory in a PC-100
system will cause the bus to operate at 66MHz, rather than the
speed it was designed to operate at.
How can I recognize compliant PC100 or PC133 SDRAM memory?
A PC100 or PC133 compliant memory includes a label affixed to
it which identifies the module as "PC100 compliant"
or "PC133 compliant " . An attempt can be made to
verify it by looking at the chip marking which should indicate
"-8" or "-7.5" after the string of manufacturer
part number, though this may not be entirely a cc urate.
What voltage is SDRAM?
SDRAM specifications state that all SDRAM has to be 3.3V.
What is the difference between "2-clock" and "4-clock"
SDRAM?
The early SDRAM DIMM design has 2 clock inputs to drive all
the SDRAM chip. This was found to be insufficient due to loading
on these inputs. Some 4 clock modules will not work in systems
that are designed for 2 clock, but some will. SOME 2 clock modules
might not work in systems designed for 4 clocks, but then again
some will.
4
clock modules are the current standard and it is unlikely to
change again.
What is
the performance difference between EDO DRAM and standard (Fast
Page Mode) DRAM?
EDO DRAM speeds up memory transactions by as little as 5% or
by as much as 25% over conventional DRAM, depending upon how
much Cache you have on your motherboard. Less Cache on the motherboard
will result in a larger speed increase when adding EDO DRAM.
EDO eliminates a wait state between the execution of sequential-read
commands from memory, giving the CPU significantly faster a
cc ess to memory.
What's the difference between 2K and 4K SDRAM?
In Short : not much, don't worry about it.
Well
the truth is :
The SDRAM has multiple internal banks. The 16M SDRAM has 2
banks, the 64M has 4 banks. When you tell the SDRAM a ROW or
COLUMN address you must also specify which BANK you are referring
to. The way to do this is by the 'bank address' (BA). Herein
lies the problem. For some unknown reasons, suppliers have lumped
together the ROW address pins with the BANK address pins and
simply refer to them as 'address' pins. For the 2Mx8 SDRAM some
suppliers claim to have 11 ROW address plus 1 BA, other just
say 12 addresses. That's just addressing, for refresh requires
you also specify the refresh interval (
tREF ). For a distributed refresh scheme you simply divide tREF
by the number of refresh cycles to get the auto-refresh interval.
In both cases for the SDRAM it works out like:
Address
bits Refresh Cycles tREF Auto-refresh interval
11 row 2^11 = 2048 = 2K 32ms 32ms / 2048 = 15.6 us
12 2^12 = 4096 = 4K 64ms 64ms / 4096 = 15.6 us
The
upshot is that for distributed refresh schemes these two devices
are identical in both addressing and refresh. (For a burst refresh
scheme, the 32ms tREF is a subset of the 64ms.)
For
the general PC application the 2K device works fine. The 4K
device offers no advantage. Note that this is not the case for
asynchronous DRAM where there truly is a difference in addressing
between 2K and 4K.
What Memory does Apple MacIntosh Computers use?
Mac Quadra 700, 900, 950, and MacIntosh II series computers
use 30 Pin SIMMs. Installation requires 4 SIMMs per bank of
the same value.
Mac
IIfx uses 64 Pin SIMM modules.
Mac
Plus, Mac SE, Mac Classics, Classic II, Color Classic, Mac LC,
LCIII, Performa 200,400, 405, 410, and 430 utilize 30 Pin SIMMs.
New
Quadras , newer Performas , and
Centris series utilize 72 Pin SIMMs.
Most
MacIntosh computers come with onboard permanent memory and can
utilize 72 Pin SIMMs 1 at a time.
Mac
Performa 6400/180 & 200 models require 168 Pin DIMMs to
upgrade.
Memory
Type: Fast Page Mode DRAM
Pentiums Computers (586 Computer)
Majority of the Pentiums computers have 2 banks of two SIMM
sockets on the motherboard, each bank must have a pair of same
value and type of memory to be utilized by the system.
Most
Pentiums computers
uses 72 Pin SIMMs. Installation requires 2 SIMMs per bank to
upgrade. (2 sockets per bank)
Typically,
Pentiums Computer with frequency of 166MHz and up have SIMM
and DIMM sockets on board and use 168 Pin DIMMs and 72 Pin SIMMs
on the same motherboard.
Pentium computers utilizing 168 Pin DIMMs require 1 DIMM at
a time, (1 socket per bank.)
Memory
Types: Generally EDO (extended data out) DRAM in matching pairs.
Older Pentium computers (60MHz -100MHz) require FPM (Fast Page
Mode DRAM.) Newer 100MHz to 200MHz MMX computers, CYRIX 6X86
and AMD 586 class processors uses EDO or FPM, and in some machines
SDRAM (DIMMs.)
486 Computers
Most 486 DX computers uses 72 Pin SIMMs. Modules may be installed
singlely ie one SIMM at a time or 1 socket per bank
Most
486 SX computer utilize 30 Pin SIMMs. Modules must be installed
in 4 pieces at one time or 4 sockets per bank.
Some
486 computers (both SX & DX) utilize both 30 Pin and 72
Pin SIMMs on the same motherboard.
Memory
Type: (FPM) Fast Page Mode DRAM, both Parity or Non-Parity,
depending on the motherboard requirements.
386 Computers
Majority of 386 computers uses 30 Pin SIMMs, though some 386
computers may use 72 Pin SIMMs.
On
386 computers, Modules must be installed in pairs. Insert two
pieces of 30 Pin SIMMs per bank.
Memory
Type: Fast Page Mode (FPM or FM)
How much memory do i need?
Very Good Question :-)) These days, when one buy a PC, it's
primary intended purpose is for speed and performance especially
capable of incredible performance for huge graphic and multimedia
application. In order for smooth efficient operation of PC with
these new memory hungry softwares, a lot more memory is required.
In the past, 8MB or 16 MB or 32MB used to be plenty enough,
but with software program increasing in size, 64MB is the least
that a Windows based PC would require. Today's PC are being
shipped with minimum 64MB and even 128MB installed. If you plan
to take advantage of the latest technology developed into new
software, you should either choose to upgrade your PC's memory
or buy one with at least 64MB or more pre-installed.
How do I know when I have enough memory?
Determining your needsThe amount of memory you need is determined
by several factors; the software, operating system and the number
of programs you want to have open at the same time. When you
determine memory needs, you'll also want to consider what your
needs will be six months down the road. If you think you may
be upgrading your operating system or adding more software,
it's a good idea to factor that into the equation now. The following
user profile will also help guide your decision:
Business
user (64MB-128MB)
~~~~~~~~~~~~~~~~~~~~~
Light to Medium usage:
runs 2 or 3 applications at one time. Mainly used for word processing,
e-mail, fax and communication, database type of application
Home
multimedia user (64MB - 128MB)
~~~~~~~~~~~~~~~~~~~~~~~~~~
Light to Heavy usage: runs 2 or 3 applications at one time.
Mainly used for word processing, e-mail, surfing the internet,
with Heavy user may include use of database, Graphics &
3D intensive games.
Graphics
user (128MB - 512MB)
~~~~~~~~~~~~~~~~~~~~
Light to heavy: runs 3 or more applications at one time. Graphic
page layout, illustration/graphics. and Heavy users also need
photo editing, font packages, multimedia and presentation software.
CAD
Design (256MB - 2GB)
~~~~~~~~~~~~~~~~~~
Light to heavy: CAD and CAM software. Heavy users need 3D CAD
and solid modeling CAM .
How Much Memory Do I Have?
It's easy to find out how much memory your PC has :
1.
From your User/Owner's Manual
Consult your user/owner's manual for details about the original
memory configuration and capacity. If you've misplaced the manual,
you may be able to contact the retailer where you bought the
PC from.
2.
If you have a hand-me-down PC or inherited a pre-owned PC, you
probably may not have the user manual or know any detail of
the original memory configuration or the memory configuration
may have been changed. Then you may want to try one of the following
options:
2a)
Ask Your PC
If your PC is running Windows NT/98/95, use the right mouse-click
on "My Computer" then select "Properties."
The total memory is calculated and displayed under the Tab that
shows "General" in the system property dialog box.
If
your PC is running Windows v 3.1 or older, go to the DOS prompt
and type in "MSD."
2b)
Ask Your Mac
If you're a Mac user, select "About This Macintosh"
or ("About This Computer") from the
Apple menu on the upper left corner of your Desktop. This will
provide info rmation about
your Mac's total memory (built-in memory plus DIMMs or SIMMs
installed).
General Guidelines for Memory Upgrade Based on CPUs
This section provides a general guideline on memory upgrades
based on your computer systems CPU. This is intended as a broad
guideline. Please consult your system user manual for further
details of your system requirement
Do I need PC100 SDRAM for my PC system?
Yes, only if you have a 100 MHz system bus. No ,if you have
a 66 MHz system bus. On certain system, a non-PC100 module may
be "pushed" to run in a 100 MHz system, but the results
are not guaranteed and may lead to system instability.
Pentium Pro Computers (P-6 Processor)
Majority of Pentium Pro P6 Computers uses 72 Pin SIMMs. Installation
requires 2 SIMMs per bank to upgrade memory. (2 sockets per
bank)
Memory
Types: Parity or Non-Parity FPM or EDO (Most have been configured
with Parity FPM)
Will more memory speed up my computer?
More memory will not increase the speed of the CPU, but it will
reduce the time a CPU spends waiting for info rmation from a
hard drive. Since RAM provides data to a CPU faster than a hard
drive, you will not have to wait as long for programs to execute.
Installing and Removing Memory Module. Replacing defective
modules and upgrading to new modules
Things needed
- new memory modules
- screwdriver (pc case removal)
- pc user manual or guide
Tips
on Memory Module Installatioon
1.
ensure environment is static safe by removing any unwanted plastic,
bags from your workbench. Keep the computer system plugged into
your AC unit but ensure that the power switch on the PC is turned
off. Keeping the PC plugged in the AC will ensure that case
is grounded thus reducing the possibility of damaging the module
or system from ESD (Electro Static Discharge )
2.
After removing the casing cover, ground yourself by touching
any of the metal surfaces on your computer casing. Doing this
step discharges any static built up on your body and
clothings
3.
Visually locate the computer memory expansion slots. This is
normal visible but if in doubt, refer to your operation manual
instruction book.
4.
Insert memory upgrade a cc ording to illustration in guide.
Take note of
- modules keyed notches and match to socket
5.
Replace case to complete installation.
Note:
when restarting your computer, note any error messages that
is being displayed and update your configuration setting a cc
ordingly.
How many modules do I need to upgrade my Pentium?
Pentium motherboards require the installation of matching pairs
when using 32 or 36 bit 72-pin memory. The motherboard is 64
bit and would necessitate the use of two 32 bit or two 36 bit
modules to equal the 64 bit
mainboard .
I just installed 16MB of memory in my 486. I turned on the computer
and get a message: Invalid configuration/run setup. How do I
fix this error?
This is not an error. This is exactly what should happen when
installing memory. Your system "sees" the new memory,
but your BIOS
does not. You must run the CMOS setup utility to allow the BIOS
to 'write' the changes in extended memory to the CMOS setup.
There are several ways to a cc ess your setup, but the normal
method is to hit your F1 or F2 key when you first boot up. Some
systems require Control+Alt+Esc , while others require the delete
key to enter setup. Check your manual for the exact key strokes.
I installed EDO memory in my Pentium system and am now encountering
boot-up problems
Try installing the EDO modules in the bank containing the OEM
(original) factory SIMMs and moving the OEM SIMMs to another
bank. Many times this will resolve the conflict. If this does
not resolve your problem, you may need to exchange the EDO modules
for Fast Page Mode (FPM) memory available at your place of purchase.
Also remember, EDO memory does not work in 486-based systems.
I have just installed memory into my 486 and have a blank monitor
or the system refuses to boot. What's wrong?
Make sure you are not trying to install EDO memory into your
system. EDO will not work in the 486 based computer .
Will EDO modules work in my 486DX2-66?
No. EDO memory is designed for Pentium style motherboards (64
bit) and will cause errors or no-boot if used in a 486 system.
Install 72-pin non-EDO memory.
What is the difference between EDO memory and Fast Page Mode
memory?
EDO memory has a faster read timing than FPM but has the same
write timing. FPM is commonly used in 386 and 486 computers,
while EDO is for Pentiums only. Apple computers should be configured
with Fast Page Mode memory.
I want to purchase Fast Page Mode memory for my 486 computer,
but the retailer only has EDO and Parity memory. What do I purchase?
EDO memory will not work in 486 computers. Parity memory, which
is actually Fast Page Mode with 4 bits for parity checking,
works in all computers. If your system does not use parity,
it will ignore it. However, if your system does require parity,
then you must use parity modules. Newer Pentium systems can
be configured to use either parity or non-parity modules but
need to have the BIOS set up a cc ordingly.
My Pentium 100Mhz computer came with EDO memory. I installed
two new EDO 60 nanosecond SIMMs and now my screen is blank when
I boot the computer. Why?
Generally speaking, EDO is for Pentiums 120Mhz and up. Most
early Pentiums (60MHz -100MHz) prefer Fast Page Mode (non-EDO)
memory. Some earlier Pentiums can use EDO , but it may require
replacing the slower standard EDO memory, and changing your
BIOS. This is not recommended for most users.
I own a Pentium 200MHz computer which has SDRAM memory. I have
one memory slot available on the mainboard for upgrading. Do
I have to remove the existing module and install in matching
pairs to upgrade my memory?
No. SDRAM or Synchronous DRAM systems utilize 64 bit, 168-pin
DIMMs rather than 72-pin SIMMs. Leave your existing memory and
install one additional module. (168-pin DIMM) Make sure the
memory is SDRAM.
What is ESD ?
ESD (Electrostatic Discharge) is Static electricity . This energy
is found in air surrounding us and can damage electronics components
in a computer such as Harddisk drive, Floppy Disk drive , motherboard
, CPU, memory modules etc.. ESD o cc urs when one touch an object
that conduct electricity.
To
protect your memory module from getting damage by ESD, always
keep electronics components in AntiStatic packaging until ready
to use.
If I have regular memory sizing error during POST ( bootup),
how should I trouble shoot the failure ?
One of the most common memory problem faced in older PC system
during boot-up is “incorrect memory sizing” or the
error number 164. Sometimes failures could be caused by incorrect
software setting, sometimes it could be caused by hardware –
which could be easily fixed if you know where the faults lies.
In
most cases hardware failures are caused by the natural aging
process of the memory components, defective memory module socket,
dirty contacts, cold solder joints during assembly and memory
module not seated properly in the socket due to vibration.
It
is important to pay attention to intermittent memory failure,
before you make any expensive decision to replace the expensive
memory - try cleaning the memory module contacts for both old
and new ram to see if the problem can be fix:
Here
‘s the How to :
Things
needed
– Contact Clean (Purchase from local computer hardware
store)
- Cotton Bud ( For cleaning contact with)
- Screwdriver (pc case removal)
- PC user manual
1
- ensure environment is static safe by removing any unwanted
plastic, bags from your workbench. Keep the computer system
plugged into your AC unit but ensure that the power switch on
the PC is turned off. Keeping the PC plugged in the AC will
ensure that case is grounded thus reducing the possibility of
damaging the module or system from ESD (Electro Static Discharge)
2
-After removing the casing cover, ground yourself by touching
any of the metal surfaces on your computer casing. Doing this
step discharges any static built up on your body and clothing
3
- Visually locate the computer memory expansion slots. This
is normal visible but if in doubt, refer to your operation manual
instruction book.
4
–
the first thing to do is to remove the memory module and perform
some visual inspection to check the memory socket which sits
the memory module. Make sure all the pins are straight, no cracks
or broken pins must be found.
A
Wet the end of a cotton swab with the solvent, the swab should
be wet but not dripping
B Using a circular motion, clean the contacts on the memory
module.
C Allow the contact surface to dry thoroughly.
D Replace the memory module into the socket.
E Repeat steps B through D for each module you have.
F Power on the computer to test the RAM.
G If you see no memory errors, replace the PC's case and power-up
away.
Additional
Tips:
5.
While contact cleaner is preferred, it is also a well-known
trick that you can also clean contacts with a pencil eraser.
6. Continuing RAM errors are usually a sign of a bad memory
module. If cleaning the contacts doesn't solve your problem,
try to isolate the faulty module and replace it.
Troubleshooting Memory Failures using AMI BIOS Beep Codes
AMI BIOS is the most popular BIOS used by most motherboard manufacturer-
you should be able to determine your system BIOS by reading
the screen display on the Top screen during power up.
Procedures
– The normal procedure is to power up the PC system, watch
for error message on the monitor screen and listen to the PC
beep tone. A single beep during boot-up process is normal and
does not indicate a failure if the system continues to boot-up.
1
Beep tone - DRAM refresh failure
2 Beep tone - DRAM Parity failure
3 Beep tone - Base 64K RAM failure
4 Beep tone - System timer error
5 Beep tone - CPU failure
6 Beep tone - Keyboard controller error
7 Beep tone - Virtual mode error
8 Beep tone - Display memory read/write error
9 Beep tone - ROM BIOS checksum error
10 Beep tone - CMOS register read/write error
11 Beep tone - Cache memory error
Continous Beep tone - Memory or Video memory failures
Guide to Troubleshooting memory using BIOS Beep Codes
The BIOS on the motherboard will always perform a power-on-self-test
“POST” during power up, usually this test is perform
to ensure proper system function and if a failure o cc urs –
the “POST” will identify the failure and emits a beeping
sound to prompt the service technician to take corrective action
ASAP.
The
exact meaning of the beeping codes varies from different BIOS
developers, there are 3 basic BIOS developer today, the most
popular BIOS is made by “American Mega-trend” - AMI,
Award and Phoenix BIOS. The beep codes for this AMI & Award
BIOS developer are provided in this memory troubleshooter guide,
we do not provide beep code reference for Phoenix BIOS and custom
BIOS written by other companies other than the two
mention .
Beep
codes are not entirely consistent sometimes to detect the exact
failures, but generally it is still the most dependent methods
to diagnose a fault without opening up the PC system or using
any diagnostic software.
My PC boots up okay but seems to hang up after running for one
hour or so. How can I find out what is wrong?
Well, this is tricky situation. Typically you may want to begin
by finding out if it's a memory related problem. DocMemory PC
Memory Diagnostic software is designed for this very purpose.
You can start by downloading a copy of the
sofware from
DocMemory Diagnostic Site , follow the setup instructions and
run a diagnostic test on your PC memory.
If
all Memory tests results returns good, you will need to isolate
and examine other possiblities such as CPU, Motherboard or other
peripherals that you have in your PC.
Some techniques for troubleshooting Memory failure without a
Memory Tester. You can attempt the following experiment:
Removing the modules one by one from motherboard
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is simplest method for isolating a failing module, but
this may apply only if the motherboard have more than one module
on the SIMM or DIMM Slot. By selectively removing module one
at a time from the system and then running the test you will
be able to find the bad module very quickly. Be sure to mark
the module that passes or when it test fails.
Swap
the modules around
~~~~~~~~~~~~~~~~~~~~~
When none of the modules can be removed, swap and rotate modules
to find which module is defective. This technique can only be
used if there are two or more modules in the system. Change
the location of two modules one at a time.
For
instances, place the module from SIMM slot 1 into slot 2 and
place the other module from slot 2 in slot 1.
Run the diagnostic test and if either the failing data bit or
address changes, you know that one of the module you have just
swap is defective. By using several combinations of module swapping
you should be able to check which module is defective.
Replacing
with known good module
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If you are unable to use either of the above two techniques,
you are left to use known good modules and selectively replace
of modules one by one to pin point the memory failure. This
is the easiest way to detect memory failure.
Removing
and cleaning the metal contacts
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If your PC system is older, sometimes dust and oxidation will
cause poor contact in the SIMM/DIMM slot. Remove the module
and clean the gold or tin contact with a “pencil eraser”
or any cleaning solution used for video and audio head cleaning.
Make sure you remember which slot is being used, and be careful
not to reverse the module while reinserting into the SIMM/DIMM
slot
Identifying
memory failure using motherboard BIOS codes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If you are not trained to perform the correct diagnostic methods
– majority BIOS developers and motherboard manufacturers
have device a simple way of telling you if your system is having
problem by emitting beeping tones from the build in speaker
on the motherboard, without the aid of a memory tester.
How do I clear the printer memory after each page is printed
1. Open the file wanted to be printed.
2.
Click on File, Print, or simply press "Ctrl P".
3.
In the Current Printer box, click on the Select menu bar.
4.
Click on Setup -> Options -> Advanced
5.
Click on the Clear Memory per Page check box.
6.
Close and Click on Print to print the file, or return to the
current file by clicking on Close.
Guide to Troubleshooting Memory Failures without a Memory Tester
This section is written with the assumption there is a general
understanding of PC operating system, in order for you to be
capable of performing the diagnostic procedures detailed below.
We
will try to describe the entire process in full detail, however
it is beyond the scope of this troubleshooter guide to provide
all the necessary info rmation to cover all possible PC system
failures. For further assistance with non-memory related failures,
please consult your PC manual or manufacturer support help online
system. If your particular question is not addressed in this
section – please send us an e-mail and we will do our best
to provide you with the right answers.
When
you are experiencing memory failures on your PC system, there
are several faults to determined, check the following:
*
PC system does not boot-up
* HIMEM.SYS does not load
* Memory failure due to system hanging up, or system rebooting
after running a large program.
* Fail to install win3.1, Win95 and Win98
* Windows program is unstable
* Continous beeping sound emitted by system during power up
*
Continous ram count during boot-
up , without loading Windows program
* No display other than blue screen on the monitor during boot-up
* Totally no video display on the monitor.
* System hang or rebooting after prolong usage.
All
of the above are typical of memory related failures, you need
to be either well trained or PC knowledgeable to be able to
perform the correct diagnostic methods.
Once
a memory failure has been detected, identifying the defective
module is not an easy task either. With a large variety of motherboard
provided by different manufacturer around the world, and with
the many different combination of SIMM/DIMM slots provided,
it would be difficult if not impossible to assemble a complete
info rmation about how a particular memory error would map to
a failing memory module.
However,
there are some basic rules that may be taken to pinpoint defective
modules using a memory diagnostic software as an aid.
Troubleshooting Memory Failures using Award BIOS Beep Codes
Award is the another popular BIOS developer and they use the
fewest beep codes by far.
Procedures
– The normal procedure is to power up the PC system, watch
for error message on the monitor screen and listen to the PC
beep tone. A single beep during boot-up process is normal and
does not indicate a failure if the system continues to boot-up.
1
Long Beep tone - Memory Problem
1 Long Beep and 2 Short Beeps - DRAM Parity failure
1 Long Beep and 3 Short Beeps - Video error
Continous Beep tone - Memory or Video memory failures
SDRAM FAQ's
What
Speed to use for Intel chipsets
440LX
- max 1GB, PC66 SDRAM
450NX
- max 8GB, PC100 SDRAM
440GX
- max 2GB, PC100 SDRAM
440BX
440ZX - Use PC100 SDRAM
What
Is Synchronous DRAM?
Synchronous
DRAM's transfer data in
lock
step with the rising edge of an applied square wave shaped clock
signal (the same clock signal that operates the memory controlling
chip set). Since the timing of synchronous DRAM is very predictable,
data can be transferred at a much higher rate than was possible
with older technologies such as EDO
or fast page mode DRAMs.
What is PC100?
PC100
is a specification for SynchronousDRAM memory modules originally
published by Intel. The specification describes, in extraordinary
detail, the requirements for an SDRAM module operating
at 100 MHz.
What is PC133?
PC133
is a specification for a 133 MHz Synchronous DRAM memory module.
It is an enhancement to the original specification
for PC100 memory modules.
What is the difference between PC100/PC133 and Rambus?
Rambus memory modules use an entirely different electrical interface
than PC100/PC133 modules. PC100/PC133 modules transfer data
at 100 (133) MHz over a 64 bit wide interface (72 bits when
using error correction). Rambus modules transfer data at 800
MHz over an 16 bit interface (18 bits when using error correction).
Rambus
is capable of transferring data at twice the overall rate of
PC100 modules (the clock is 8 times faster and the interface
is 1/4 as wide).
What
is Double Data Rate SDRAM?
Double
data rate SDRAM transfers data on both rising and falling edges
of an applied square wave shaped clock signal. Therefore, a
PC266 DDR memory module can transfer data twice as fast as a
PC133 SDRAM module.
What
is ECC?
Typical
memory controllers read and write 64 bits of data at a time
to and from memory modules that do not support ECC. 8 additional
bits are required to support ECC (72 bit memory modules). Systems
using ECC (Error Detection and Correction) can automatically
correct any single bit error in any of the 72 bits. They can
detect two bit errors. ECC is used in mission critical applications
so
that the system will not crash if a memory cell loses data.
What
are registered modules?
There
are two types of SDRAM module organizations, unbuffered (also
known as unregistered) and registered. Registered modules have
additional components (registers) placed between the incoming
address and control information and the SDRAM components. These
modules are typically used in Servers due to their added reliability
(they place much less of an electrical load on the memory controller
and therefore make it possible to have as many as 16 or 32 modules
in a large system).
What
is Serial Presence Detect?
Serial
Presence Detect (or SPD) information is stored inside of a special
component on the memory module. The component is called an EEPROM.
The information is read by the computer's BIOS during boot to
tell the computer how to properly configure the memory controller
for the memory modules that are installed in the system.
What
is CAS Latency?
CAS
latency refers to the number of clock cycles between the application
of the SDRAM's column address and the appearance of the data
at the output of the module. It serves as a performance indicator.
A CAS latency 2 module requires 2 clocks between the application
of the column address and the data. This is one clock faster
than a CAS latency 3 module. Systems using CAS latency 2 (CL2)
SDRAM's are typically a few percent faster than systems using
CAS latency 3 SDRAM's.
RAM
diagnostic utilities
Memtest-86
3.0
http://www.memtest86.com./
MemTest
v1.2 [9k] W9x/2k/XP - free - http://www.mywebattack.com/gnomeapp.php?id=105570
and
http://www.simmtester.com/page/products/doc/download.asp
