On Sat, Dec 15, 2001 at 01:51:26PM +0100, Lennart Augustsson wrote:
> Wojciech Puchar wrote:
> 
> > i found infos about 2-way pentium-III servers accepting 6 GB of RAM.
> >
> > HOW is it addressed?!?!
> 
> There are plenty of address lines from the chip (I forget exactly how many, 40?).
> To access it from software you need to change the memory mappings since
> you can only see 4G at a time.

It's called PAE (Physical Address Extensions), allowing for 36-bit
physical addresses. It's all hidden in the page table, which has
entried widened to 64 bits, so that the 36 bits of physical address
fit in there. Virtual address space is still 32 bits wide.

- Frank

-- 
Frank van der Linden                           fvdl@wasabisystems.com
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