A7V333 filling 3 Memory Banks

[JJJ]

I have a A7V333 and have (2) 256m Crucial (CT3264Z335) Modules tat
have been working for some time now. I decided to add another 256 and
now I am starting to have some weird problems. When I try to run a
Quicktime .mov file it starts ok then all of a sudden the audio goes
to a buzzing hum and my DSL connection locks up. I have to reboot so
as to clear all of this up. This 256 module is the same as the rest
and is recommended by crucial. When I take this out everything works
just fine. I tried switching modules but had no success. Is there an
issue with filling up this 3 slots of memory in this MB? Is there
something I can do so I can run 3 256mn Modules?

 

[Daniel Mandic]

JJJ wrote:


Hi!



You could write more data: which CPU, type and specification of the
ram, FSB Speed etc. etc..??

I will give you some options which might help coming closer.....

Lower the FSB Speed, e.g from 166 to 133MHz (266), don`t care about the
underclocked CPU. Lower the RAM speed - CL2 to CL3 (slower). If the CPU
won´t let underclock, like my AthlonXP1800 not running with 100 instead
of 133 :-( then you can just try to lower everything in the BIOS,
concerning the RAM-Access, except the FSB-Speed.
Take the third DIMM instead of the first one and leave the third free,
test it. Then you can see if the new RAM-DIMM is possibly broken, at
least.

Till then.




Best Regards,

Daniel Mandic


P.S.: Be sure to turn off the power when changing the dimms....

 

[Paul]

I have a A7V333 and have (2) 256m Crucial (CT3264Z335) Modules tat
have been working for some time now. I decided to add another 256 and
now I am starting to have some weird problems. When I try to run a
Quicktime .mov file it starts ok then all of a sudden the audio goes
to a buzzing hum and my DSL connection locks up. I have to reboot so
as to clear all of this up. This 256 module is the same as the rest
and is recommended by crucial. When I take this out everything works
just fine. I tried switching modules but had no success. Is there an
issue with filling up this 3 slots of memory in this MB? Is there
something I can do so I can run 3 256mn Modules?

There is an insert page to download, that adds to your manual.

http://dlsvr03.asus.com/pub/ASUS/mb/socka/kt333/a7v333/ie1010_a7v333.pdf

It says:

"Three (3) sockets are available for both 266MHz-PC2100 or 200MHz-
PC1600 DDR DIMMs to form a memory size of 64MB to 3GB. Only
two (2) DIMMs will support 333MHz-PC2700; if more than two 333MHz
DIMMs are installed, the system automatically reverts to a maximum
speed of 266MHz."

Apparently, that slowdown from DDR333 to DDR266 is BIOS version dependent.
It is possible it won't happen with the later releases of BIOS.

The problem with having three slots on a DDR memory bus, is it is
loading dependent. The electrical signals look their best with one
stick of RAM. As you add RAM, the signals get worse and worse.
Driving three double sided sticks is the worst.

The above fix, slowing down the RAM clock, gives extra time for the
electrical signal levels to stabilize, on each clock cycle.

You choices are:

1) Use a memory configuration that has one or two sticks of RAM.
Either buy a quality single 1GB module, using 64Mx8 chip type,
or buy 2x512MB DIMMs. You could even return the 256MB to
Crucial, get a single 512MB DIMM from them, and run 1x256 + 1x512.

2) Slow down the memory clock. Look in your user manual and the
BIOS setup screen, to figure out how to do it. On motherboards
where the memory speed cannot be adjusted separate from the
processor FSB, this means a slowdown in computing performance,
and is why this might not be an acceptable solution. (I think
I see an option to run asynchronous in your manual, so maybe
you can use FSB333 and DDR266 settings for example. I don't
know what your processor's FSB is, so that is just an example.)

Also, experimenting by running Quicktime and waiting for a crash,
is not a good way to determine your memory and CPU are happy.
I recommend two free test tools. Memtest86+ from www.memtest.org
will prepare a standalone boot floppy for you, and once the
computer is booted with that floppy, you should run the test
error free for at least two full passes. The second tool is
Prime95 from mersenne.org . Prime95 runs in Windows, and has
a "torture test" as one of many options. The "torture test"
carries out an extended calculation, with a known answer, and
thrashes both memory and CPU. Bad memory will error out in half
an hour or less. You can run that test overnight and see if
it will run error free - make sure the cooling on your
computer is adequate for the job, as Prime95 will make the CPU
get hot. Use Asus Probe/Speedfan/MBM5 to check the CPU temp
during the first 15 minutes or so, and stop the test if things
are getting too hot. If your cooling is good, there shouldn't
be a problem running the test for longer periods.

Once you pass those two tests, running Quicktime should not
cause any more problems.

Paul

 

[Egil Solberg]

I have a A7V333 and have (2) 256m Crucial (CT3264Z335) Modules tat
have been working for some time now. I decided to add another 256 and
now I am starting to have some weird problems. When I try to run a
Quicktime .mov file it starts ok then all of a sudden the audio goes
to a buzzing hum and my DSL connection locks up. I have to reboot so
as to clear all of this up. This 256 module is the same as the rest
and is recommended by crucial. When I take this out everything works
just fine. I tried switching modules but had no success. Is there an
issue with filling up this 3 slots of memory in this MB? Is there
something I can do so I can run 3 256mn Modules?

Most probably you use a FSB266 processor. The selling point for the A7V333
when it first came out was the possibility to run FSB and RAM
asynchronously, now with the amazing memory speed of "DDR333". It turned
out from benchmarks that the DDR333 feature was not worth much without
support for FSB333 as well. To sum it up, it is best to run memory at the
same speed as FSB. It will probably help with your stability problems.

 

[Daniel Mandic]

It says:

"Three (3) sockets are available for both 266MHz-PC2100 or 200MHz-
PC1600 DDR DIMMs to form a memory size of 64MB to 3GB. Only
two (2) DIMMs will support 333MHz-PC2700; if more than two 333MHz
DIMMs are installed, the system automatically reverts to a maximum
speed of 266MHz."

Apparently, that slowdown from DDR333 to DDR266 is BIOS version
dependent. It is possible it won't happen with the later releases of
BIOS.

Paul

Really? A KT333 does not accept more than three dimms at 133MHz?



Best Regards,

Daniel Mandic

 

[Egil Solberg]

Really? A KT333 does not accept more than three dimms at 133MHz?

I'm reading Paul as if it does not support more than 2 at 166MHz. He didn't
mention how many modules are supported at 133MHz.

http://www.anandtech.com/mb/showdoc.html?i=1636&p=19

There are some boards mentioned here with 4 slots. It could be interesting
to download manuals for those boards to see what kind of memory config was
allowed.

 

[Paul]

I'm reading Paul as if it does not support more than 2 at 166MHz. He didn't
mention how many modules are supported at 133MHz.

http://www.anandtech.com/mb/showdoc.html?i=1636&p=19

There are some boards mentioned here with 4 slots. It could be interesting
to download manuals for those boards to see what kind of memory config was
allowed.

Interesting. I took a look at the manual for this one:

http://www.shuttle.com/Share/simages/productimages/ak35gt2r.jpg

It has four DIMM slots. Three DIMM slots can be populated with
double sided DIMMs at DDR333 rates. At that speed, Asus only
claims to be able to support two double sided DIMMs.

In terms of what the designer can influence, all the boards
will be using the same Northbridge chip. The designer can
play with the termination networks for the DIMM busses,
and the designer can play with the impedance selected for the
copper tracks that connect the DIMM slots. Perhaps small
changes there can influence whether the memory bus works
best when more heavily loaded, or when more lightly loaded.

The rules for DIMM speed versus number of slots are just
rules of thumb. JEDEC tries to make the behaviors reproducible,
by specifying that all modules have the same capacitance on
the lines etc. So at least JEDEC wants to see consistent
behavior. But not everyone else will see things that way.

There is an option on the KT333 for Command Rate
2T. It is actually the default on the A7V333. The board
will be more stable with three sticks, if it is set to use
Command Rate 2T for the address bus to the memory.

This article is one of the ones that shaped my opinion of
how hard this stuff is to get right. This article discusses
doing DDR333 on just two slots. The file is a 5MB download.

http://download.micron.com/pdf/technotes/TN4607.pdf

Paul

 

[Daniel Mandic]

Interesting. I took a look at the manual for this one:

http://www.shuttle.com/Share/simages/productimages/ak35gt2r.jpg

It has four DIMM slots. Three DIMM slots can be populated with
double sided DIMMs at DDR333 rates. At that speed, Asus only
claims to be able to support two double sided DIMMs.

In terms of what the designer can influence, all the boards
will be using the same Northbridge chip. The designer can
play with the termination networks for the DIMM busses,
and the designer can play with the impedance selected for the
copper tracks that connect the DIMM slots. Perhaps small
changes there can influence whether the memory bus works
best when more heavily loaded, or when more lightly loaded.

The rules for DIMM speed versus number of slots are just
rules of thumb. JEDEC tries to make the behaviors reproducible,
by specifying that all modules have the same capacitance on
the lines etc. So at least JEDEC wants to see consistent
behavior. But not everyone else will see things that way.

There is an option on the KT333 for Command Rate
2T. It is actually the default on the A7V333. The board
will be more stable with three sticks, if it is set to use
Command Rate 2T for the address bus to the memory.

This article is one of the ones that shaped my opinion of
how hard this stuff is to get right. This article discusses
doing DDR333 on just two slots. The file is a 5MB download.

http://download.micron.com/pdf/technotes/TN4607.pdf

Paul

Hi Paul!



All at all, I would not run a 266FSB-DDR AMD with 333 RAM, as this
board can. It is not a KT333A or a KT400!!!
Even a 333FSB-AMD (like a Barton) in this Board , I would also run
with 266. Gives an underclocked Barton, but at least synchron. So far I
know, only the RAM may be 333MHz, the Chipset just can 266FSB,
respective 133MHz.

Who cares.....




Best Regards,

Daniel Mandic

 

[JJJ]

There is an insert page to download, that adds to your manual.

http://dlsvr03.asus.com/pub/ASUS/mb/socka/kt333/a7v333/ie1010_a7v333.pdf

It says:

"Three (3) sockets are available for both 266MHz-PC2100 or 200MHz-
PC1600 DDR DIMMs to form a memory size of 64MB to 3GB. Only
two (2) DIMMs will support 333MHz-PC2700; if more than two 333MHz
DIMMs are installed, the system automatically reverts to a maximum
speed of 266MHz."

Apparently, that slowdown from DDR333 to DDR266 is BIOS version dependent.
It is possible it won't happen with the later releases of BIOS.

The problem with having three slots on a DDR memory bus, is it is
loading dependent. The electrical signals look their best with one
stick of RAM. As you add RAM, the signals get worse and worse.
Driving three double sided sticks is the worst.

The above fix, slowing down the RAM clock, gives extra time for the
electrical signal levels to stabilize, on each clock cycle.

You choices are:

1) Use a memory configuration that has one or two sticks of RAM.
Either buy a quality single 1GB module, using 64Mx8 chip type,
or buy 2x512MB DIMMs. You could even return the 256MB to
Crucial, get a single 512MB DIMM from them, and run 1x256 + 1x512.

2) Slow down the memory clock. Look in your user manual and the
BIOS setup screen, to figure out how to do it. On motherboards
where the memory speed cannot be adjusted separate from the
processor FSB, this means a slowdown in computing performance,
and is why this might not be an acceptable solution. (I think
I see an option to run asynchronous in your manual, so maybe
you can use FSB333 and DDR266 settings for example. I don't
know what your processor's FSB is, so that is just an example.)

Also, experimenting by running Quicktime and waiting for a crash,
is not a good way to determine your memory and CPU are happy.
I recommend two free test tools. Memtest86+ from www.memtest.org
will prepare a standalone boot floppy for you, and once the
computer is booted with that floppy, you should run the test
error free for at least two full passes. The second tool is
Prime95 from mersenne.org . Prime95 runs in Windows, and has
a "torture test" as one of many options. The "torture test"
carries out an extended calculation, with a known answer, and
thrashes both memory and CPU. Bad memory will error out in half
an hour or less. You can run that test overnight and see if
it will run error free - make sure the cooling on your
computer is adequate for the job, as Prime95 will make the CPU
get hot. Use Asus Probe/Speedfan/MBM5 to check the CPU temp
during the first 15 minutes or so, and stop the test if things
are getting too hot. If your cooling is good, there shouldn't
be a problem running the test for longer periods.

Once you pass those two tests, running Quicktime should not
cause any more problems.

Paul

I went into the Bios settings and under advanced- CPU/Memory Frequency
Ratio I changed it from Auto to 4:5. I guess it was not auto switching
to 266 when inserting the third module. Everything works fine now.
Thanks