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SubjectRe: Using >1GB RAM
"Albert D. Cahalan" <acahalan@cs.uml.edu> writes:

>> no, the PPro 'bigphys' feature extends physical memory space to 64G
>> (actually extends it to 64 bits, but i guess the CPU itself is 64G
>> limited), but logical address space will stay pure 32 bits.

>The Pentium Pro feature extends physical memory, while the old
>segmentation hack extends virtual memory to 48 bits.

>The only 32-bit limits would be the stack, the code, and the
>size of individual data objects. Total data can be huge.

No. Your adress goes throuth the segmentation MMU, and you get a
*32* bit linear address. This goes throuth the page tables, and
you get a 36 bit physical address. You can't access more than
4GB at once. If you want to use more than 4GB, you have to switch
page tables.

Gerd

--
"Wo kämen wir hin, wenn alle sagten, wo kämen wir hin, und niemand ginge
hin, um einmal zu schauen, wohin man käme, wenn man ginge." -- Kurt Marti

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