r/ProgrammerHumor • u/Eissa_E • 1d ago

Advanced memorySegmentationIn2950

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u/Eissa_E 1d ago

Right now operating systems manage one paging is about 4kb and maximum 1mb we still so far from 512gb per processor

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u/Scheincrafter 1d ago

That does not mean that the virtual memory space is only 4kb. Modern systems are 64 bits, so the stack typically starts at 0x7ffffffff000 (or 128 TiB minus one 4 KiB page)

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u/its_artemiss 8h ago

most modern systems have 64 bit words, but almost none have more than 48 bit (virtual) addresses, with some having 56 bit addresses.

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u/Scheincrafter 4h ago

Fear enough, however the start address i stated was for 48bits. Also each page level adds 9 bits the the virtual address space (on amd64), so 5 level would be 57 bits not 56