[rescue] Memory upgrade in Dell PowerEdge 2560

Meelis Roos mroos at linux.ee
Thu May 28 00:23:32 CDT 2015

> With the working stick you should use something like CPU-Z to read the
> actual SPD table from a stick of the problem RAM to see what JDEC timings
> the stick is presenting to the motherboard.  Some memory does not include a
> complete set of JDEC timings for slower speeds, and some motherboards are
> very picky if the RAM installed in them doesn't having the timings for the
> speed the motherboard expects.  In Linux you can use decode-dimms with some
> extra setup it looks like:

Yes, exactly. And because some faster DIMMs lack the tables for lower 
speeds, they do not work in computer using the lower speeds.

An example was a quad PowerMac G5 that required PC2-4200 DIMMs and 
random faster DDR2 DIMMs did not work. After using a tool to reprogram 
the SPD EEPROM to also include timings for slower speed, the RAM started 

Meelis Roos (mroos at linux.ee)

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