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Old March 22nd 06, 02:50 AM posted to alt.comp.periphs.mainboard.asus
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Default KV8-MX - How to set memory timing

In article , Shadow sh@dow wrote:

On Tue, 21 Mar 2006 03:11:01 GMT, (Paul) wrote:

In article , Shadow

sh@dow wrote:

Cant find it. Using DDR 400, but unstable. Want to try 300.
Cant find it in manual or actual bios.
TIA


Have you tried "Memclock Mode" set to [Manual] ?
The user manual claims more settings will be exposed if you
try that setting, but there are no pictures of the new
settings you will see.

Paul


Thanks, the option was grayed out and I assumed it could not be
changed.
My memory is Kingston 3200

Any idea what the best settings might be ?

The bios had defaulted to 200Mz bus
I changed that to 400Mz (2:1), and I must confess, no difference felt
at all.

TIA


Get a copy of CPUZ (
www.cpuid.com/cpuz.php ) and verify the
resulting settings.

The "CPU" panel shows you the clock fed to the CPU (200.9MHz in
this example).

http://www.xtremenews.net/datos/arti...0+-2-2-2-5.jpg

In the "Memory" panel, the frequency shown is the one fed to the
RAM. The frequency is made, by dividing the core clock by the memory
divider (shown on the next line of the panel as "CPU/11" in this
example). The memory clock is 200.9MHz, which is DDR402. If the
person running this motherboard had selected a lower value in the
BIOS, this clock would be different than the one feeding the CPU.

http://www.xtremenews.net/datos/arti...0+-2-2-2-5.jpg

This is an example of an overclocked memory. The clock here is
280.9MHz, which is DDR562, and is very high by conventional
standards.

http://www.xtremenews.net/datos/arti...c2-a8n-MEM.jpg

The parameters that have the most effect on the memory bandwidth,
are the memory frequency and the Command Rate setting. From lowest
performance to highest performance, they would be

DDR333 Command Rate 2T
DDR333 Command Rate 1T
DDR400 Command Rate 2T
DDR400 Command Rate 1T (fastest)

Which setting is appropriate, depends on how many sticks of RAM
are installed in the motherboard, and which slots they are in.
Your manual is missing the normal "Table 1", but you can see
the recommended settings on page 21 of this manual:

http://www.asus.com/pub/ASUS/mb/sock.../e1721_k8n.pdf

The memory operation is a function of the CPU and not the
chipset, and that is why the Table 1 of the K8N manual can
be applied to the operation of your motherboard.

AMD also makes a technical document available, which they
have updated a number of times. Table 42 on PDF page 175
contains the same information as in the Asus manual Table 1.
The two columns on the right, show the maximum memory rate,
when the Command Rate is set to 1T (command per clock) or
2T (command per every two clocks). If you are using two
sticks of RAM, they should go in slot 1 and slot 3. AMD
says two sticks are only capable of DDR333, but you can try
a higher setting than that.

http://www.amd.com/us-en/assets/cont...docs/26094.PDF

When you adjust the memory subsystem, and especially if the
memory is being overclocked, you should test the memory with
memtest86+ from http://www.memtest.org . It is important to
boot with the memtest86+ floppy first, and test the memory,
because if you just boot into Windows, your Windows install
could be corrupted. So be careful with your memory experiments.

HTH,
Paul