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Re: Only 3.6gb of 64gb RAM recognized by 64bit squeeze



On Thu, May 10, 2012 at 8:16 PM, Stan Hoeppner <stan@hardwarefreak.com> wrote:
On 5/10/2012 12:47 AM, Mohtadin Hashemi wrote:
> Sorry for double and top post. Pushed the wrong button.
>
> I was saying that the RAM are all Mushkin 996770, i was also going to buy a SuperMicro board as i have very good experience with those but i had to wait 1 mo th for it, time that i dont have. Again i went with the Mushkin dimms because i could get them quickly, otherwise i would have bought kingston rdimms which i use in all my other computers.
>
> I now know that my kingston dimms don't work on the board, so it must be a BIOS issue. I say this because in the BIOS changelog there is an entry for update concerning RAM not recognized by OS, which they claim has been fixed.

Socket G34 is able to work with 8x 4GB SR or DR unbuffered DIMMs at
1333MHz at 1.5v, even 1600Mhz at 1.5v with 6200 series CPUs.  So this
may be a board specific problem.  You mentioned that removing 4 DIMMs
allowed Debian to recognize 48GB.  Try this...

With all 16 DIMMs installed, enter the system BIOS and change "Memory
CLK" in the Advanced/Northbridge menu to 533MHz, save and reboot.  This
should drop the memory bus frequency from 1333 to 1066.  If the problem
is due to electrical bus loading at 1333MHz, lowering the freq may help.
 This is probably a log shot, but worth testing as it's quick/simple.

If this doesn't fix the issue, and memtest and other utils can see all
64GB just fine, then I'd say you're dealing with a BIOS bug.

BTW, you originally mentioned you pulled all 16 sticks from a production
server that had run fine for months/years, and installed them in this
system.  Now you tell use you ordered the 16 Mushkin sticks for this
build.  This conflicting story leads me to wonder exactly what memory
you have, where you're being straight with us, and where you're not.
Makes it really hard to assist in this troubleshooting effort when we
don't know what information is reliable.


--
Stan
 
I have not been clear then: The RAM that was pulled from a working environment was/is 6 Kingston RDIMMs with 8GB each.
The Mushkin RAM was ordered specifically for this server/board.
 
As for lowering the frequency, I did actually try; both 533 and 400 MHz - neither helped.
 
I wrote a few e-mails back that the 48GB config does not work anymore - lending more credential to the "BIOS is at fault" theory. I have not touched the OS, just reset CMOS every time I have changed RAM modules.
 
Other things I have tried are:
1) Disable the 2nd CPU via BIOS and install only one 8GB DIMM - this did not work, again only 3.5GB was shown.
1.a) Disable the 2nd CPU and install two 4GB DIMMs - does not work.
2) Gradually increase 4GB DIMM count from 2 to 16 - the same result as all the other times.
 
I don't know any other utilities that do a similar job as memtest, otherwise I would have tried it. As it is now, only memtest and BIOS can recognize all 64GB RAM.

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