Technical question on motherboard

[feenberg-fCu/yNAGv6M at public.gmane.org (Daniel Feenberg)]

On Fri, 1 Jan 2010, Jerry Feldman wrote:

> At work I've got 4 systems that are using a Supermicro X7DB8+
> motherboards. 3 of these systems happily are set up with 64GB (16 4GB
> Kingston memory sticks). The 4th system is having trouble recognizing
> the 4GB sticks. When we originally got the memories for the other
> systems, we had to download and flash a BIOS. But, this last system
> still does not work with the 4Gb sticks. When I originally put them in,
> the machine did boot, but hung on udev. Now, I can't even get the system
> to come up in the BIOS. (note that I wear an anti-static strap when
> replacing the memories so zapping the memories should not come into play).
>
> I've reflashed the BIOS a few times. One possible suggestion I received
> was to change the 1GB PCI memory hole from 256 to 1GB.
>
> One clue is that I do receive a message: "0251: System CMOS checksum bad
> - Default configuration used".
>
> I'm just looking for some suggestions, or some help to carry the system
> to the roof so I can export it to the parking lot.
>

We have such a system, it works with 4 GB sticks but had a tendency to 
crash with all the memory slots filled. It also came with an ethernet 
remote console that we have not been able to make work.

As for your problem, don't you think you have a defective CMOS chip?  I 
have had good luck buying replacement CMOS chips from 
http://www.biosman.com or maybe Supermicro would send a replacement 
without having you return the board, or you could swap chips with one of 
your working systems, if you can afford to have 2 down at once.

Daniel Feenberg

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> Jerry Feldman <gaf-mNDKBlG2WHs at public.gmane.org>
> Boston Linux and Unix
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