Messages in this thread | | | Date | Wed, 14 Jan 1998 09:42:53 +0100 | From | Gerd Knorr <> | Subject | Re: Using >1GB RAM |
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"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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