A8N-SLI - what memory settings to use?

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fsda

OK, this is likely a dumb question. Although I'm very fluent in computers,
I am new to the AMD platform...

I have an A8N-SLI, and bought four Kingston ValueRAM DIMMs, totalling 2GB,
which are listed on the Asus QVL, and also specified on this list to work
in this configuration on the A8N-SLI.

I have NO interest in overclocking whatsoever. (I have enough fun with
video driver instability when in SLI mode that I am not worried about
overclocking and risking additional crashes to gain small percentage
increases in speed...)

My RAM is rated as DDR400. However, when putting four DIMMs in the Asus
A8N-SLI, the motherboard automatically slows down the DIMMs to 333MHz.
This is stated on the Asus website that it does this to improve
compatability, and it also says that for RAM on the QVL, it is ok to
manually put it back to DDR400 in the BIOS.

Up until now I had been setting the Max Clock for the RAM in the BIOS to
400MHz. I left all the other settings in Auto.

Tonight I upgraded the BIOS to version 1007. Now, I can set the RAM
settings in the BIOS to full Auto. However, if I want to specify the RAM
clock speed (i.e. set it to 400MHz), I now have to specify _all_ the other
timing settings, too.

How do I figure out what to set the other RAM timing settings to? Again, I
have no interest in overclocking - I just want to run the DIMMs at the
factory recommended speed.

Is there some kind of utility that can read the RAM factory timing ratings
so that I know how to set this in the BIOS?

Thanks in advance for the help.
 
OK, this is likely a dumb question. Although I'm very fluent in computers,
I am new to the AMD platform...

I have an A8N-SLI, and bought four Kingston ValueRAM DIMMs, totalling 2GB,
which are listed on the Asus QVL, and also specified on this list to work
in this configuration on the A8N-SLI.

I have NO interest in overclocking whatsoever. (I have enough fun with
video driver instability when in SLI mode that I am not worried about
overclocking and risking additional crashes to gain small percentage
increases in speed...)

My RAM is rated as DDR400. However, when putting four DIMMs in the Asus
A8N-SLI, the motherboard automatically slows down the DIMMs to 333MHz.
This is stated on the Asus website that it does this to improve
compatability, and it also says that for RAM on the QVL, it is ok to
manually put it back to DDR400 in the BIOS.

Up until now I had been setting the Max Clock for the RAM in the BIOS to
400MHz. I left all the other settings in Auto.

Tonight I upgraded the BIOS to version 1007. Now, I can set the RAM
settings in the BIOS to full Auto. However, if I want to specify the RAM
clock speed (i.e. set it to 400MHz), I now have to specify _all_ the other
timing settings, too.

How do I figure out what to set the other RAM timing settings to? Again, I
have no interest in overclocking - I just want to run the DIMMs at the
factory recommended speed.

Is there some kind of utility that can read the RAM factory timing ratings
so that I know how to set this in the BIOS?

Thanks in advance for the help.
Click to expand...

Try A64tweaker, written by "CodeRed". While it can be used to
set the memory in Windows, I'd just use it to list RAM
settings.

http://www.akiba-pc.com/download.php?view.40
http://www.xtremesystems.org/forums/showthread.php?s=&threadid=37345

You could also try www.cpuid.com/cpuz to list RAM parameters.
As you note, DDR400 with a command rate setting of 2T, is likely
the best setting that will be stable for four DIMMs. One poster
here tested DDR333 command rate 1T, and got less performance than
with DDR400 command rate 2T.

You could go back to the old BIOS, collect the data you need for setup
after using the old BIOS, then flash back up to the new BIOS, and
enter the settings into the BIOS setup screen. Afterward, verify
with A64tweaker again, that the BIOS has faithfully copied
the settings (BIOS don't always work as advertised).

This document from AMD defines the parameters - look around chapter 4.
The doc didn't help me much, but you can compare the comments from other
users against the official definitions given by AMD:

http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26094.PDF

Looking on the CPUZ web page, it says there is a module to dump the
contents of the SPD on the DIMM. You might have a look at that, if you
want to see the contents of the individual bytes in the SPD
EEPROM that the AMD 26094 doc refers to.

There is an old program called CTSPD, that was used to dump the SPD
EEPROM, but it is getting pretty old, and programs like that need
constant maintenance.

Paul
 
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