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Is 128 bit the limit of what we would need? We use 128 bit UUIDs. 2^256 seems to be more than the number of atoms on Earth.
by tayistay 4y ago
Is 128 bit the limit of what we would need? We use 128 bit UUIDs. 2^256 seems to be more than the number of atoms on Earth.
- wongarsu 4y agoThe article does talk about just making the pointer type used in syscalls 256 bit wide to "give room for any surprising future needs". The size of large networked disk arrays will grow beyond 64 bit addresses, but I don't think we will exceed 2^128 bits of storage of any size, for any practical application. Then again, there's probably people who thought the same about 32 bit addresses when we moved from 16bit to 32bit addresses. The most likely case for "giant" pointers (more than 128 bits) will be adding more metadata into the pointer. With time we might find enough use cases that are worth it to go to 256bit pointers, with 96bit address and 160 bit metadata or something like that.
- dylan604 4y ago>Then again, there's probably people who thought the same about 32 bit addresses when we moved from 16bit to 32bit addresses. There's a fun "quote" about 384k being all anyone would ever need, so clearly everyone just needs to settle down and figure out how to refactor their code.
- shadowofneptune 4y agoThe IBM PC's 20-bit addressing was 16 times the size of 16-bit addresses. From 20-bit to 32-bit, 4096 times larger. 32 to 64 is 4,294,967,296 times larger (!). The scale alone makes using all this space unlikely on a PC.