4 GB RAM showing up as 3, BIOS memory hole and all that

Martin Nilsson martin at gneto.com
Wed Aug 17 14:37:03 GMT 2005

Scott Long wrote:
> not do the remapping and result in you loosing effective RAM.  The
> difference between Intel and AMD is because AMD puts the memory
> controller into the CPU instead of in the PCI host bridge, so it's much
> harder to have the two work together to do the remapping.  I believe
> that there are some Opteron systems that can do this, though.

The E stepping Opteron can remap memory. The earlier versions can't.
The 252 and above is only avalable as rev. E, the slower models are 
being replaced in the near future. In order to use the remap feature 
your motherboard BIOS must know about it and have settings for memory remap.


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