[coreboot] K8 machine with (a lot of) ram from 2 vendors keeps resetting

Marc Jones marcj303 at gmail.com
Thu Sep 3 00:03:45 CEST 2009

Hi Ward,

On Wed, Sep 2, 2009 at 3:14 PM, Ward Vandewege<ward at gnu.org> wrote:
> Hi all,
> I'm having some problems with a supermicro h8dme board with 2 K8 processors
> and 64 GB of ram.
> Sadly, the ram is of two types (that was not my decision :/). We have 8x 4GB
> Samsung M393T5160QZA-CE6 and 8x 4GB Kingston KVR667D2D4P5/4G. Both of these
> types of ram are dual rank DDR2, 667 MHz, CL5, 1.8 V, registered, ECC.
> The memory is installed like this:
> BANK     CPU1        CPU2
> 1B       KING        KING
> 1A       KING        KING
> 2B       KING        KING
> 2A       KING        KING
> 3B       SAMS        SAMS
> 3A       SAMS        SAMS
> 4B       SAMS        SAMS
> 4A       SAMS        SAMS
> With the proprietary BIOS, this setup works perfectly. That said, the manual
> for the board does say it's not recommended to mix memory types. Our system
> integrator mentions that when 16 banks are used, the memory runs at maximum
> 533MHz.

As we talked about, it looks like the memory is sized correctly and
the next thing to try forcing the memory speed slower. 8 dual rank
dimms (16 banks) s[eed limitation might be spec'd or errata. A check
might need to go into the main k8 mem init code.



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