brand name ?

[Jack Tseng]

I have Asus K8N and A7V333. I plan to upgrade to 1GB PC3200 ram on the both.
What brand name do you recommend ?

thanks!
Jack

[Paul]

Post by Jack Tseng
I have Asus K8N and A7V333. I plan to upgrade to 1GB PC3200 ram on the both.
What brand name do you recommend ?
thanks!
Jack

For 1GB DDR, first of all, don't buy the sticks from Ebay. Ebay
carries the unbranded DIMMs with 128Mx4 chips on them, and you
should buy branded DIMMs (some brand name printed on them) with
branded chips (memory company brand name printed on the chips).
Branded memory will use 64Mx8 chips and will work better with
your machine.

If you know little about memory, and just want the selection
process to be over with, go to

www.crucial.com
www.kingston.com

and use their search engines. They will give you a list of
products compatible with your motherboards. In fact, some
of the products offered, appear to be common to both motherboards.

If you are shopping on price, then I would use the following
selection process. Go to www.newegg.com , go to the page with
system memory products offered.

http://www.newegg.com/Product/ProductList.asp?Submit=ENE&N=2000170147+1052107965+1052307858&Subcategory=147

Then, find a product that has many customer reviews. It means
people have been buying them for some reason. Then read the
reviews. Some memory will have many DOAs (dead on arrival) reports.
Other RAM may have reports of failures after X months of use.
Reports of successful overclocking of the memory, means the RAM
is more than capable of operating at the necessary speed (select
PC3200 for universal usage in your machines). By going through
the list of RAM products, with the list sorted by price, and
reviewing the customer feedback, you'll get some idea of whether
there is a brand of memory that is safe for consumption.
(The JEDEC standard for DDR memory is CAS3, and memory rated at
CAS2.5 or CAS2 has faster first cycle access. On motherboards
that are picky about RAM, sometimes the lower CAS memory works
better. If you see numbers like 2-3-2-5, the CAS is the first
digit. Lower CAS memory is also more expensive.)

This is a sample of a customer review page, with various
people's tales of woe. You want a page like this with as
many glowing reports as possible. A large sample size
prevents one person from filing multiple reports and
upsetting the statistics.

http://www.newegg.com/Product/CustratingReview.asp?Item=N82E16820141166

It helps to have a warranty on RAM. I bought cheap RAM from my
local computer stores, and two batches went bad after the 1
year warranty was up. I've been buying memory from Crucial since
then, and none of those sticks have failed.

It is your money and your gamble. The memory business is
cutthroat enough, that all kinds of shortcuts on testing
are used, to give the cheapest selling price possible. And
that is why a warranty and good after sales support help.

When you get the memory, immediately test with memtest86+ from
memtest.org . The auto setting in the BIOS should extract
the proper timing parameters from the SPD info stored on
the new DIMMs. One parameter that doesn't get set correctly
is the voltage for the DIMMs. On some motherboards, there is
a BIOS option to set the voltage. 2.6V is the JEDEC standard
for PC3200 DDR, and sometimes using 2.7V will help if the
memory reports the odd error. On older motherboards, the
voltage set by jumpers is probably already boosted enough
to do the job without fussing with it. In any case, if
you have problems, you can always come back here and get
some help.

Once the memory has been tested, only then is it safe to
boot into Windows. You don't just slap memory into the
machine and immediately boot, as the memory could be
bad. Using memtest86+ is good to eliminate as much as
possible, the chance of corrupting the registry in
Windows, due to the RAM being bad.

Once memtest86+ has done two complete passes (there is a
pass counter on the screen), then it is safe to quit the
program and boot into Windows (or Linux). Once in Windows,
a good test for the memory, is to use a copy of Prime95
from mersenne.org . There is an option in there called the
"torture test", and it performs a calculation with a
known answer. If any errors are detected in the calculation,
you will be informed by the program. Prime95 is a more
sensitive test that your computer is working properly,
and one hour of testing in Prime95 is worth hundreds of
hours of sitting idle in the Windows desktop, waiting for
the computer to crash. If you have passed Prime95 testing
for hours on end, there is reason to assume your new
memory purchase has been a successful one.

I would repeat the Prime95 test at yearly intervals, just
to see if the memory remains in pristine condition. For
one of my failed memories, that is how I detected it.

Paul

[Barry Watzman]

"E-Bay" doesn't carry anything. E-Bay is just a venue for bringing
buyers and sellers together. There are thousands of sellers, who carry
everything .... branded, unbranded, "as-is", or "with warranty". I'm
not saying that E-Bay is the best source, it may or may not be, but you
can get whatever you want on E-Bay, you just have to know enough to
recognize what is being sold and what you want and compare the two.

Post by Paul

Post by Jack Tseng
I have Asus K8N and A7V333. I plan to upgrade to 1GB PC3200 ram on the both.
What brand name do you recommend ?
thanks!
Jack

For 1GB DDR, first of all, don't buy the sticks from Ebay. Ebay
carries the unbranded DIMMs with 128Mx4 chips on them, and you
should buy branded DIMMs (some brand name printed on them) with
branded chips (memory company brand name printed on the chips).
Branded memory will use 64Mx8 chips and will work better with
your machine.
If you know little about memory, and just want the selection
process to be over with, go to
www.crucial.com
www.kingston.com
and use their search engines. They will give you a list of
products compatible with your motherboards. In fact, some
of the products offered, appear to be common to both motherboards.
If you are shopping on price, then I would use the following
selection process. Go to www.newegg.com , go to the page with
system memory products offered.
http://www.newegg.com/Product/ProductList.asp?Submit=ENE&N=2000170147+1052107965+1052307858&Subcategory=147
Then, find a product that has many customer reviews. It means
people have been buying them for some reason. Then read the
reviews. Some memory will have many DOAs (dead on arrival) reports.
Other RAM may have reports of failures after X months of use.
Reports of successful overclocking of the memory, means the RAM
is more than capable of operating at the necessary speed (select
PC3200 for universal usage in your machines). By going through
the list of RAM products, with the list sorted by price, and
reviewing the customer feedback, you'll get some idea of whether
there is a brand of memory that is safe for consumption.
(The JEDEC standard for DDR memory is CAS3, and memory rated at
CAS2.5 or CAS2 has faster first cycle access. On motherboards
that are picky about RAM, sometimes the lower CAS memory works
better. If you see numbers like 2-3-2-5, the CAS is the first
digit. Lower CAS memory is also more expensive.)
This is a sample of a customer review page, with various
people's tales of woe. You want a page like this with as
many glowing reports as possible. A large sample size
prevents one person from filing multiple reports and
upsetting the statistics.
http://www.newegg.com/Product/CustratingReview.asp?Item=N82E16820141166
It helps to have a warranty on RAM. I bought cheap RAM from my
local computer stores, and two batches went bad after the 1
year warranty was up. I've been buying memory from Crucial since
then, and none of those sticks have failed.
It is your money and your gamble. The memory business is
cutthroat enough, that all kinds of shortcuts on testing
are used, to give the cheapest selling price possible. And
that is why a warranty and good after sales support help.
When you get the memory, immediately test with memtest86+ from
memtest.org . The auto setting in the BIOS should extract
the proper timing parameters from the SPD info stored on
the new DIMMs. One parameter that doesn't get set correctly
is the voltage for the DIMMs. On some motherboards, there is
a BIOS option to set the voltage. 2.6V is the JEDEC standard
for PC3200 DDR, and sometimes using 2.7V will help if the
memory reports the odd error. On older motherboards, the
voltage set by jumpers is probably already boosted enough
to do the job without fussing with it. In any case, if
you have problems, you can always come back here and get
some help.
Once the memory has been tested, only then is it safe to
boot into Windows. You don't just slap memory into the
machine and immediately boot, as the memory could be
bad. Using memtest86+ is good to eliminate as much as
possible, the chance of corrupting the registry in
Windows, due to the RAM being bad.
Once memtest86+ has done two complete passes (there is a
pass counter on the screen), then it is safe to quit the
program and boot into Windows (or Linux). Once in Windows,
a good test for the memory, is to use a copy of Prime95
from mersenne.org . There is an option in there called the
"torture test", and it performs a calculation with a
known answer. If any errors are detected in the calculation,
you will be informed by the program. Prime95 is a more
sensitive test that your computer is working properly,
and one hour of testing in Prime95 is worth hundreds of
hours of sitting idle in the Windows desktop, waiting for
the computer to crash. If you have passed Prime95 testing
for hours on end, there is reason to assume your new
memory purchase has been a successful one.
I would repeat the Prime95 test at yearly intervals, just
to see if the memory remains in pristine condition. For
one of my failed memories, that is how I detected it.
Paul

[Jack Tseng]

I have the installed 2 x Samsung 256MB DDR333 for A7V333, total 512MB.. I
want upgrading to 1.5GB. One simm slot is available. Can I put 1GB Samsung
DDR400 in slot #3 ? Another is K8N, 2 x Samsung 512MB, are installed,
total 1GB, I plan to put extra 1GB Samsung DDR400, total 2GB. Do they sound
right? Samsung uses 64Mx8 chips? which is better and mroe stable? 128Mx4 or
64Mx8 chips?

Thanks!
Jack

Post by Paul

Post by Jack Tseng
I have Asus K8N and A7V333. I plan to upgrade to 1GB PC3200 ram on the both.
What brand name do you recommend ?
thanks!
Jack

For 1GB DDR, first of all, don't buy the sticks from Ebay. Ebay
carries the unbranded DIMMs with 128Mx4 chips on them, and you
should buy branded DIMMs (some brand name printed on them) with
branded chips (memory company brand name printed on the chips).
Branded memory will use 64Mx8 chips and will work better with
your machine.
If you know little about memory, and just want the selection
process to be over with, go to
www.crucial.com
www.kingston.com
and use their search engines. They will give you a list of
products compatible with your motherboards. In fact, some
of the products offered, appear to be common to both motherboards.
If you are shopping on price, then I would use the following
selection process. Go to www.newegg.com , go to the page with
system memory products offered.
http://www.newegg.com/Product/ProductList.asp?Submit=ENE&N=2000170147+1052107965+1052307858&Subcategory=147
Then, find a product that has many customer reviews. It means
people have been buying them for some reason. Then read the
reviews. Some memory will have many DOAs (dead on arrival) reports.
Other RAM may have reports of failures after X months of use.
Reports of successful overclocking of the memory, means the RAM
is more than capable of operating at the necessary speed (select
PC3200 for universal usage in your machines). By going through
the list of RAM products, with the list sorted by price, and
reviewing the customer feedback, you'll get some idea of whether
there is a brand of memory that is safe for consumption.
(The JEDEC standard for DDR memory is CAS3, and memory rated at
CAS2.5 or CAS2 has faster first cycle access. On motherboards
that are picky about RAM, sometimes the lower CAS memory works
better. If you see numbers like 2-3-2-5, the CAS is the first
digit. Lower CAS memory is also more expensive.)
This is a sample of a customer review page, with various
people's tales of woe. You want a page like this with as
many glowing reports as possible. A large sample size
prevents one person from filing multiple reports and
upsetting the statistics.
http://www.newegg.com/Product/CustratingReview.asp?Item=N82E16820141166
It helps to have a warranty on RAM. I bought cheap RAM from my
local computer stores, and two batches went bad after the 1
year warranty was up. I've been buying memory from Crucial since
then, and none of those sticks have failed.
It is your money and your gamble. The memory business is
cutthroat enough, that all kinds of shortcuts on testing
are used, to give the cheapest selling price possible. And
that is why a warranty and good after sales support help.
When you get the memory, immediately test with memtest86+ from
memtest.org . The auto setting in the BIOS should extract
the proper timing parameters from the SPD info stored on
the new DIMMs. One parameter that doesn't get set correctly
is the voltage for the DIMMs. On some motherboards, there is
a BIOS option to set the voltage. 2.6V is the JEDEC standard
for PC3200 DDR, and sometimes using 2.7V will help if the
memory reports the odd error. On older motherboards, the
voltage set by jumpers is probably already boosted enough
to do the job without fussing with it. In any case, if
you have problems, you can always come back here and get
some help.
Once the memory has been tested, only then is it safe to
boot into Windows. You don't just slap memory into the
machine and immediately boot, as the memory could be
bad. Using memtest86+ is good to eliminate as much as
possible, the chance of corrupting the registry in
Windows, due to the RAM being bad.
Once memtest86+ has done two complete passes (there is a
pass counter on the screen), then it is safe to quit the
program and boot into Windows (or Linux). Once in Windows,
a good test for the memory, is to use a copy of Prime95
from mersenne.org . There is an option in there called the
"torture test", and it performs a calculation with a
known answer. If any errors are detected in the calculation,
you will be informed by the program. Prime95 is a more
sensitive test that your computer is working properly,
and one hour of testing in Prime95 is worth hundreds of
hours of sitting idle in the Windows desktop, waiting for
the computer to crash. If you have passed Prime95 testing
for hours on end, there is reason to assume your new
memory purchase has been a successful one.
I would repeat the Prime95 test at yearly intervals, just
to see if the memory remains in pristine condition. For
one of my failed memories, that is how I detected it.
Paul

[Paul]

Post by Jack Tseng
I have the installed 2 x Samsung 256MB DDR333 for A7V333, total 512MB.. I
want upgrading to 1.5GB. One simm slot is available. Can I put 1GB Samsung
DDR400 in slot #3 ? Another is K8N, 2 x Samsung 512MB, are installed,
total 1GB, I plan to put extra 1GB Samsung DDR400, total 2GB. Do they sound
right? Samsung uses 64Mx8 chips? which is better and mroe stable? 128Mx4 or
64Mx8 chips?
Thanks!
Jack

Well, I'm not sure you are going to like the answer :-)

DDR memory busses are loading sensitive. When you use all
three slots, sometimes the memory clock must be slowed down
in order for the memory to work error free. The manual may
have said the motherboard supports 3GB, but it usually doesn't
admit what speed the memory was running at the time.

With the A7V333:

The memory controller is most likely to run two double sided
sticks at DDR333. With three double sided sticks present,
a rate of DDR266 is more likely to work. When you add the
third stick, you'll have to test the combined memory
and see if it works well. (My comments are a _guide_ and
your results may vary. If you saw what the signals on the
memory bus looked like, you'd realize why. Memory sticks
have tiny differences in construction, and no two will
perform the same from an electrical perspective.)

For the first test, install the new 1GB module in the third
slot, and remove the two other sticks. Use your memtest86+
boot disk to test the new memory. If any errors show up,
then there is a problem with the new memory.

If the single stick does at least two full passes of memtest86+,
you can try booting into Windows. Get a copy of CPUZ from
www.cpuid.com and make note of the memory timing and frequency
information for the new DIMM (even if it is PC3200, it will
only run at DDR333 because that is the chipset limit on your
board - so that would be normal).

Now, shut down, unplug the computer, and add the other two
sticks of memory (unplugging the computer is to make sure
no power is present in the RAM slots when you install the
DIMMs). Now, power up again, and have a look in the BIOS.
If the memory was running at DDR333 before, the BIOS may
automatically set it to DDR266 with the three sticks
present. You can repeat the memtest86+ testing, allowing
two full passes before booting into Windows. In Windows
you can verify the timings and frequency with CPUZ.

I'm not sure whether that board can be successfully overridden
or not. You can try setting the memory speed to DDR333 in the
BIOS, while the three sticks are present, but the setting
may not stay there. Have a look in Google and see what the
history of the DDR settings is. It may be a function of
the release of BIOS used, among other things.

With the K8N:

In this case, there is a table in the manual (Table 1). The
tradeoff of memory speed, versus what memory is used, is shown
in detail. The last entry in the table, shows three DIMMs
running at DDR200. But things will not likely be that bad,
and you may squeeze more performance from the memory than
that.

That table of information is provided by AMD. The memory
controller is inside the processor on your K8N, and AMD tested
the memory drive capabilities of the board, to make that
table of information. Not all motherboard manufacturers pass
the table to customers, without altering the contents. So
you may find that slightly different tables exist in different
brands of motherboard manuals. In any case, the table originated
with AMD, and the 26094.PDF document (table 42) from AMD is where
you would look for the original table, if needed.

The socket 754 AMD processor has two address busses. One bus
drives slot 1, while the other bus drives slot 2 and 3. So at
least populating slot 1 is not likely to overload its address
bus. That might be a good place to stick the new DIMM.

Line 18 in the table in your manual, has an entry that shows
two sticks, one in slot 1 and one in slot 3, running at DDR400
as well.

The question will be, whether it makes sense to use the third
(512MB) DIMM or not. The memory clock rate is going to have
to be reduced, or the "Command Rate" setting will have to be
changed from 1T to the more relaxed 2T setting. No matter what
you do, the memory bandwidth seen in synthetic benchmarks is
going to have to drop. In terms of fastest to slowest performance:

DDR400 memory with Command Rate 1T
DDR400 memory with Command Rate 2T (20% less bandwidth due to 2T)
DDR333 memory with Command Rate 1T (20% less bandwidth due to clock)
DDR333 memory with Command Rate 2T (worse)

With one stick of RAM, the first setting might work. With
two sticks of RAM in slot 1 and slot 3, either the first or
the second setting might work. When you have all three
sticks installed, it might be the third or fourth setting
which works properly. You'll have to experiment a bit, to
get the best memory bandwidth, while at the same time
checking for error free performance. The Vdimm setting in
the BIOS can be bumped up a bit (2.7V, 2.75V or so) in
an attempt to improve this.

Knowing the memory you currently own, I would take the
two new 1GB sticks and use them in the K8N. Use slot 1
and slot 3. Take the two 512MB sticks from the K8N and
plug them into the A7V333. With the remaining 256MB sticks,
if you want, you can stick one of them into the A7V333
and see if it is stable with 512+512+256 total RAM.
If it was me, I'd run with 512+512 in slot 1 and slot 3
of the A7V333. With only two sticks in the K8N, I think
you'll have a bit less trouble tuning it up.

The moral of the story is, with single channel memory busses,
it doesn't always make sense to use all the slots. There
is a tradeoff of number of sticks versus the speed they will
run at, and more than a few people I've dealt with, are
unwilling to compromise on the speed. And that generally
means using two slots, and finding the biggest modules
which are compatible with the chipset (1GB). But with
all the memory sticks you'll have on hand, you can do
the experiments for yourself, and see what works well.

Regarding the 128Mx4 or 64Mx8 question. The 4 or 8 on the
end of the number, is the width of the data bus on the memory
chip used. With the 64Mx8 chips, it takes eight chips to make
a 64 bit wide bank of memory. The data bus on a DIMM is 64
bits wide. With the total of sixteen chips, there are two
independent banks on the DIMM. Control signals for a bank
only drive eight loads.

With the 128Mx4 chips, it takes sixteen chips to make a 64 bit
wide bank. Thus the whole DIMM is needed to make a bank. Some
of the control signals have sixteen loads as a result. JEDEC
does not approve of this construction technique (only
registered DIMMs are supposed to be constructed with
sixteen chips per bank, and not unbuffered DIMMs).

If you read this advert:

http://www.portatech.com/catalog/memory.asp?ID=285

you'll notice the DIMM constructed with the 128Mx4 chips is
in the right hand column. Notice the warning printed just
above the price. There is a restricted set of chipsets
capable of driving the DIMM. And it doesn't say whether those
chipsets are happy driving three of those DIMMs or not.
The price may be cheaper, but your usage of the DIMMs could
be restricted. For the extra $18, you can have a DIMM that
is unrestricted in how it can be used (subject to the
limitations of bus loading, as discussed above, where
you end up trading off memory bus speed versus the number
of sticks).

Have fun,
Paul

[Jack Tseng]

Thank you, Paul...

I changed my mind, 2 x Samsung DDR400 512MB are moved from K8N to A7V333. I
will remove 2 x Samsung 256MB DDR333 from A7V333. I plan to order 2 x
Samsung, 1GB for K8N. Does it sound good ?

I found the advest,
http://4magicus.com/samsungmm-400.html

Tell me what you think of Samsung 1GB DDR400...

Thanks!
Jack

Post by Paul

Post by Jack Tseng
I have the installed 2 x Samsung 256MB DDR333 for A7V333, total 512MB.. I
want upgrading to 1.5GB. One simm slot is available. Can I put 1GB Samsung
DDR400 in slot #3 ? Another is K8N, 2 x Samsung 512MB, are installed,
total 1GB, I plan to put extra 1GB Samsung DDR400, total 2GB. Do they sound
right? Samsung uses 64Mx8 chips? which is better and mroe stable? 128Mx4 or
64Mx8 chips?
Thanks!
Jack

Well, I'm not sure you are going to like the answer :-)
DDR memory busses are loading sensitive. When you use all
three slots, sometimes the memory clock must be slowed down
in order for the memory to work error free. The manual may
have said the motherboard supports 3GB, but it usually doesn't
admit what speed the memory was running at the time.
The memory controller is most likely to run two double sided
sticks at DDR333. With three double sided sticks present,
a rate of DDR266 is more likely to work. When you add the
third stick, you'll have to test the combined memory
and see if it works well. (My comments are a _guide_ and
your results may vary. If you saw what the signals on the
memory bus looked like, you'd realize why. Memory sticks
have tiny differences in construction, and no two will
perform the same from an electrical perspective.)
For the first test, install the new 1GB module in the third
slot, and remove the two other sticks. Use your memtest86+
boot disk to test the new memory. If any errors show up,
then there is a problem with the new memory.
If the single stick does at least two full passes of memtest86+,
you can try booting into Windows. Get a copy of CPUZ from
www.cpuid.com and make note of the memory timing and frequency
information for the new DIMM (even if it is PC3200, it will
only run at DDR333 because that is the chipset limit on your
board - so that would be normal).
Now, shut down, unplug the computer, and add the other two
sticks of memory (unplugging the computer is to make sure
no power is present in the RAM slots when you install the
DIMMs). Now, power up again, and have a look in the BIOS.
If the memory was running at DDR333 before, the BIOS may
automatically set it to DDR266 with the three sticks
present. You can repeat the memtest86+ testing, allowing
two full passes before booting into Windows. In Windows
you can verify the timings and frequency with CPUZ.
I'm not sure whether that board can be successfully overridden
or not. You can try setting the memory speed to DDR333 in the
BIOS, while the three sticks are present, but the setting
may not stay there. Have a look in Google and see what the
history of the DDR settings is. It may be a function of
the release of BIOS used, among other things.
In this case, there is a table in the manual (Table 1). The
tradeoff of memory speed, versus what memory is used, is shown
in detail. The last entry in the table, shows three DIMMs
running at DDR200. But things will not likely be that bad,
and you may squeeze more performance from the memory than
that.
That table of information is provided by AMD. The memory
controller is inside the processor on your K8N, and AMD tested
the memory drive capabilities of the board, to make that
table of information. Not all motherboard manufacturers pass
the table to customers, without altering the contents. So
you may find that slightly different tables exist in different
brands of motherboard manuals. In any case, the table originated
with AMD, and the 26094.PDF document (table 42) from AMD is where
you would look for the original table, if needed.
The socket 754 AMD processor has two address busses. One bus
drives slot 1, while the other bus drives slot 2 and 3. So at
least populating slot 1 is not likely to overload its address
bus. That might be a good place to stick the new DIMM.
Line 18 in the table in your manual, has an entry that shows
two sticks, one in slot 1 and one in slot 3, running at DDR400
as well.
The question will be, whether it makes sense to use the third
(512MB) DIMM or not. The memory clock rate is going to have
to be reduced, or the "Command Rate" setting will have to be
changed from 1T to the more relaxed 2T setting. No matter what
you do, the memory bandwidth seen in synthetic benchmarks is
DDR400 memory with Command Rate 1T
DDR400 memory with Command Rate 2T (20% less bandwidth due to 2T)
DDR333 memory with Command Rate 1T (20% less bandwidth due to clock)
DDR333 memory with Command Rate 2T (worse)
With one stick of RAM, the first setting might work. With
two sticks of RAM in slot 1 and slot 3, either the first or
the second setting might work. When you have all three
sticks installed, it might be the third or fourth setting
which works properly. You'll have to experiment a bit, to
get the best memory bandwidth, while at the same time
checking for error free performance. The Vdimm setting in
the BIOS can be bumped up a bit (2.7V, 2.75V or so) in
an attempt to improve this.
Knowing the memory you currently own, I would take the
two new 1GB sticks and use them in the K8N. Use slot 1
and slot 3. Take the two 512MB sticks from the K8N and
plug them into the A7V333. With the remaining 256MB sticks,
if you want, you can stick one of them into the A7V333
and see if it is stable with 512+512+256 total RAM.
If it was me, I'd run with 512+512 in slot 1 and slot 3
of the A7V333. With only two sticks in the K8N, I think
you'll have a bit less trouble tuning it up.
The moral of the story is, with single channel memory busses,
it doesn't always make sense to use all the slots. There
is a tradeoff of number of sticks versus the speed they will
run at, and more than a few people I've dealt with, are
unwilling to compromise on the speed. And that generally
means using two slots, and finding the biggest modules
which are compatible with the chipset (1GB). But with
all the memory sticks you'll have on hand, you can do
the experiments for yourself, and see what works well.
Regarding the 128Mx4 or 64Mx8 question. The 4 or 8 on the
end of the number, is the width of the data bus on the memory
chip used. With the 64Mx8 chips, it takes eight chips to make
a 64 bit wide bank of memory. The data bus on a DIMM is 64
bits wide. With the total of sixteen chips, there are two
independent banks on the DIMM. Control signals for a bank
only drive eight loads.
With the 128Mx4 chips, it takes sixteen chips to make a 64 bit
wide bank. Thus the whole DIMM is needed to make a bank. Some
of the control signals have sixteen loads as a result. JEDEC
does not approve of this construction technique (only
registered DIMMs are supposed to be constructed with
sixteen chips per bank, and not unbuffered DIMMs).
http://www.portatech.com/catalog/memory.asp?ID=285
you'll notice the DIMM constructed with the 128Mx4 chips is
in the right hand column. Notice the warning printed just
above the price. There is a restricted set of chipsets
capable of driving the DIMM. And it doesn't say whether those
chipsets are happy driving three of those DIMMs or not.
The price may be cheaper, but your usage of the DIMMs could
be restricted. For the extra $18, you can have a DIMM that
is unrestricted in how it can be used (subject to the
limitations of bus loading, as discussed above, where
you end up trading off memory bus speed versus the number
of sticks).
Have fun,
Paul

[Paul]

Post by Jack Tseng
Thank you, Paul...
I changed my mind, 2 x Samsung DDR400 512MB are moved from K8N to A7V333. I
will remove 2 x Samsung 256MB DDR333 from A7V333. I plan to order 2 x
Samsung, 1GB for K8N. Does it sound good ?
I found the advest,
http://4magicus.com/samsungmm-400.html
Tell me what you think of Samsung 1GB DDR400...
Thanks!
Jack

That advertisement says "6ns speed" and PC3200. The number
should be 5ns. The inverse of 5ns is 200MHz, doubling gives
DDR400. If a memory has a speed of 6ns, the inverse of 6ns
is 166MHz, doubling that gives DDR333 or PC2700. So the
numbers in the advert are not consistent.

When shopping for 1GB memory, look for two things:

1) Proof that 64Mx8 chips are used. Many adverts will not
tell you this and it is important information. An explicit
statement that 64Mx8 chips are used, is protection against
buying a module with 128Mx4 chips.

2) Find a web site like Newegg, that has customer reviews. You
can use the Newegg site, to find good brands and model numbers
of memory modules. Then shop on other web sites for the exact
same memory (checking the manufacturer's part numbers are
the same). Some of the products on the Newegg memory web pages
have better reputations than others. And that is how I judge
whether they are candidates or not. Modules with a high DOA
rate, or reports that the modules don't overclock, are
not the ones you want.

You will be tempted by many bargains. But ask yourself the
question - how is this (small company) able to offer me a
bargain ? A small company cannot buy in enough bulk to give
good prices, and they will be tempted to use a lower price
module to do the job. And that is where the 128Mx4 chips come
in (since they are cheaper). All I can suggest to you, is find
a product that properly specifies what you are buying.

Paul

Post by Jack Tseng

Post by Paul

Post by Jack Tseng
I have the installed 2 x Samsung 256MB DDR333 for A7V333, total 512MB.. I
want upgrading to 1.5GB. One simm slot is available. Can I put 1GB Samsung
DDR400 in slot #3 ? Another is K8N, 2 x Samsung 512MB, are installed,
total 1GB, I plan to put extra 1GB Samsung DDR400, total 2GB. Do they sound
right? Samsung uses 64Mx8 chips? which is better and mroe stable? 128Mx4 or
64Mx8 chips?
Thanks!
Jack

Well, I'm not sure you are going to like the answer :-)
DDR memory busses are loading sensitive. When you use all
three slots, sometimes the memory clock must be slowed down
in order for the memory to work error free. The manual may
have said the motherboard supports 3GB, but it usually doesn't
admit what speed the memory was running at the time.
The memory controller is most likely to run two double sided
sticks at DDR333. With three double sided sticks present,
a rate of DDR266 is more likely to work. When you add the
third stick, you'll have to test the combined memory
and see if it works well. (My comments are a _guide_ and
your results may vary. If you saw what the signals on the
memory bus looked like, you'd realize why. Memory sticks
have tiny differences in construction, and no two will
perform the same from an electrical perspective.)
For the first test, install the new 1GB module in the third
slot, and remove the two other sticks. Use your memtest86+
boot disk to test the new memory. If any errors show up,
then there is a problem with the new memory.
If the single stick does at least two full passes of memtest86+,
you can try booting into Windows. Get a copy of CPUZ from
www.cpuid.com and make note of the memory timing and frequency
information for the new DIMM (even if it is PC3200, it will
only run at DDR333 because that is the chipset limit on your
board - so that would be normal).
Now, shut down, unplug the computer, and add the other two
sticks of memory (unplugging the computer is to make sure
no power is present in the RAM slots when you install the
DIMMs). Now, power up again, and have a look in the BIOS.
If the memory was running at DDR333 before, the BIOS may
automatically set it to DDR266 with the three sticks
present. You can repeat the memtest86+ testing, allowing
two full passes before booting into Windows. In Windows
you can verify the timings and frequency with CPUZ.
I'm not sure whether that board can be successfully overridden
or not. You can try setting the memory speed to DDR333 in the
BIOS, while the three sticks are present, but the setting
may not stay there. Have a look in Google and see what the
history of the DDR settings is. It may be a function of
the release of BIOS used, among other things.
In this case, there is a table in the manual (Table 1). The
tradeoff of memory speed, versus what memory is used, is shown
in detail. The last entry in the table, shows three DIMMs
running at DDR200. But things will not likely be that bad,
and you may squeeze more performance from the memory than
that.
That table of information is provided by AMD. The memory
controller is inside the processor on your K8N, and AMD tested
the memory drive capabilities of the board, to make that
table of information. Not all motherboard manufacturers pass
the table to customers, without altering the contents. So
you may find that slightly different tables exist in different
brands of motherboard manuals. In any case, the table originated
with AMD, and the 26094.PDF document (table 42) from AMD is where
you would look for the original table, if needed.
The socket 754 AMD processor has two address busses. One bus
drives slot 1, while the other bus drives slot 2 and 3. So at
least populating slot 1 is not likely to overload its address
bus. That might be a good place to stick the new DIMM.
Line 18 in the table in your manual, has an entry that shows
two sticks, one in slot 1 and one in slot 3, running at DDR400
as well.
The question will be, whether it makes sense to use the third
(512MB) DIMM or not. The memory clock rate is going to have
to be reduced, or the "Command Rate" setting will have to be
changed from 1T to the more relaxed 2T setting. No matter what
you do, the memory bandwidth seen in synthetic benchmarks is
DDR400 memory with Command Rate 1T
DDR400 memory with Command Rate 2T (20% less bandwidth due to 2T)
DDR333 memory with Command Rate 1T (20% less bandwidth due to clock)
DDR333 memory with Command Rate 2T (worse)
With one stick of RAM, the first setting might work. With
two sticks of RAM in slot 1 and slot 3, either the first or
the second setting might work. When you have all three
sticks installed, it might be the third or fourth setting
which works properly. You'll have to experiment a bit, to
get the best memory bandwidth, while at the same time
checking for error free performance. The Vdimm setting in
the BIOS can be bumped up a bit (2.7V, 2.75V or so) in
an attempt to improve this.
Knowing the memory you currently own, I would take the
two new 1GB sticks and use them in the K8N. Use slot 1
and slot 3. Take the two 512MB sticks from the K8N and
plug them into the A7V333. With the remaining 256MB sticks,
if you want, you can stick one of them into the A7V333
and see if it is stable with 512+512+256 total RAM.
If it was me, I'd run with 512+512 in slot 1 and slot 3
of the A7V333. With only two sticks in the K8N, I think
you'll have a bit less trouble tuning it up.
The moral of the story is, with single channel memory busses,
it doesn't always make sense to use all the slots. There
is a tradeoff of number of sticks versus the speed they will
run at, and more than a few people I've dealt with, are
unwilling to compromise on the speed. And that generally
means using two slots, and finding the biggest modules
which are compatible with the chipset (1GB). But with
all the memory sticks you'll have on hand, you can do
the experiments for yourself, and see what works well.
Regarding the 128Mx4 or 64Mx8 question. The 4 or 8 on the
end of the number, is the width of the data bus on the memory
chip used. With the 64Mx8 chips, it takes eight chips to make
a 64 bit wide bank of memory. The data bus on a DIMM is 64
bits wide. With the total of sixteen chips, there are two
independent banks on the DIMM. Control signals for a bank
only drive eight loads.
With the 128Mx4 chips, it takes sixteen chips to make a 64 bit
wide bank. Thus the whole DIMM is needed to make a bank. Some
of the control signals have sixteen loads as a result. JEDEC
does not approve of this construction technique (only
registered DIMMs are supposed to be constructed with
sixteen chips per bank, and not unbuffered DIMMs).
http://www.portatech.com/catalog/memory.asp?ID=285
you'll notice the DIMM constructed with the 128Mx4 chips is
in the right hand column. Notice the warning printed just
above the price. There is a restricted set of chipsets
capable of driving the DIMM. And it doesn't say whether those
chipsets are happy driving three of those DIMMs or not.
The price may be cheaper, but your usage of the DIMMs could
be restricted. For the extra $18, you can have a DIMM that
is unrestricted in how it can be used (subject to the
limitations of bus loading, as discussed above, where
you end up trading off memory bus speed versus the number
of sticks).
Have fun,
Paul