RAM SPD / Auto ?

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A little advice/help needed :-)

I've just installed som OCZ DDR RAM PC3200 into my PC (Abit AN8 MoBo)
after a double helping of Crucial Ballistix problems and was just
wondering what was the correct settings to apply in the BIOS/CMOS etc,
RAM timings?  I had it set manual for the Ballistix, slowed down the
timings to stop the majority of BSoD's. I now have new OZC RAM
(2x512MB Matched Pair) and set it to SPD? Should I set this to Auto?
Also the Ballistix were 2.8v, so I have now set the OCZ to 2.6v,
should this also be something that is automatically detected and set?
I only ask as I want to be sure I have things set correctly to get
some confidence with it all.

Many thanks

Keith (Southend)

Re: RAM SPD / Auto ?

On 27 Feb 2007 03:19:15 -0800, keith_harris9@hotmail.com

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Set it to Auto/SPD until you have reason to do otherwise.

If you think that it's using correct timings then check it
in CPU-Z, compare the two tabs for actual timings used to
the SPD programmed timings.

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Did you test it with memtest86+ before ever running the OS?
You could now have file corruption, it is always best to not
boot windows until you feel memory is stable.

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There is no need to ask about specific modules, the first
try with any and all memory combinations should be to

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No, voltage is not automatically set.  Set it to what OCZ
rated as appropriate for the spec'd speed.  With a
motherboard having poor memory power circuit, you might need
to raise it a notch or two beyond that, or with general (not
exceptionally high spec'd memory) modules you might just
leave the board bios set to auto and test that.

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If you want to try manual settings of timings, consult the
memory specs provided by the manufacturer, but also search
for data about your particular motherboard model, as it
could have particular issues making it necessary to use more
conservative settings to retain stability in certain

Re: RAM SPD / Auto ?

keith_harris9@hotmail.com wrote:
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Timing is stored in the SPD on the DIMM, but the custom voltage setting
are not, for DDR memory. (There is a non-standard way to do it for DDR2,
but if you follow JEDEC only, there isn't a way there either. Byte 8
in the SPD states the nominal voltage value to be used.)

JEDEC SPD spec for DDR memory, so you can see what is in there...

You only use enough voltage to get the job done. The Ballistix is not
a high voltage memory, and 2.8V could well be the max, not an invitation
to set them at 2.8V the instant you get them.

On some DRAM chips at least, the chip has a voltage regulator inside.
Which means excess voltage is simply dumped as heat. Where the extra
voltage might be helping, is on the I/O pads.

When you get new RAM, set it to Auto in the BIOS, and then you can review
the settings it used later, with a Windows utility. Some enthusiast
RAM, rated to run above PC3200, will only have PC3200 timings in the SPD,
to allow the motherboard to run the first time the memory is used. That
means, you may need to set up the memory manually, to get to the value
stated in the product advertising.

On an S939 board, the memory controller is inside the processor. With a
single pair of RAM, you should be able to run DDR400 rate, with Command
Rate set to 1T (one command per clock cycle, on the address bus). When
using two pairs of sticks, many BIOS will drop this, and use DDR333 rate
or perhaps drop the Command Rate to 2T (one command for every two clock
cycles). The extended Command Rate, allows time for the command to settle
on a heavily loaded address bus. (The BIOS design follows the instructions
provided by AMD, for use with their processors. But that doesn't stop the
end user from being more aggressive. Finding errors is what tells you
that you've gone too far.)

Apply only enough voltage for stability. You can start at 2.6 to 2.7V, and
use memtest86+ to check for errors. If there were only a couple errors
in a few complete passes, then maybe a voltage increase might make a
difference. But it could just as well be, that the RAM is not really
as speedy as the label claims. At least with the Ballistix, there is
half a chance they will use good test techniques. (Since the DIMM could
have been made in a Micron plant.) I have four sticks of Ballistix, running
dual channel in two computers, and have no complaints about them.


Re: RAM SPD / Auto ?

Thank you both for your replies, I'll have another look at my BIOS and
RAM settings when I get home tonight.

I have had two sets of Ballistix Pairs of memory which worked fine for
six months then faulting modules and BSoD's. From another forum I was
advised to set some manual timings, which worked for a time (a number
of weeks) before the problems started again. The first set I finally
did a Memtest86 on and overnight got about 10,000 errors. Crucial
replaced like for like without any question. The second set followed
the same pattern, although the last time I did run Memtest for about 4
hours, found no errors. However, because I require a stable system as
it runs 24/7 uploading my weather data, I decided to go for OCZ as I
had lost confidence in the Crucial Ballistix sticks. I'm not the only

(Amazon.com product link shortened)


When I first installed the OCZ ones I set to SPD and the voltage to
2.6v, however the first boot came up with an error:
And I couldn't stop the send error messages to microsoft.
Ran scandisc, found nor problems and since then it has behaved, well
it hasn't crashed as I can still see my weather data uploaded ever 15
minutes, any subsequent reboots I did last night have not presented me
with anymore errors. However, I'm not convinced all is well and hence
my initial post. I run AVG, AdAware and Search & Destroy and have a
NAT Firewall.

I will try 'Auto' tonight and see how I get on, I remember trying this
with the Ballistix a while ago and it wouldn't even boot into windows.

Again, thanks for helping

Keith (Southend)

Re: RAM SPD / Auto ?

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Set to Auto, rebooted, no apparent problems.
CPU-Z shows the same timings on both tabs (SPD).
Generally feels more stable, but thats just a gut feeling.

Keith (Southend)

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