Why we don’t have 128 bit OS or CPUs?
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A better question would be, why *would* we have 128 CPUs?
32 bit architecture gives us 2^32 values, a bit over 4 billion, which more or less sets the limit for memory addresses, capping your RAM at 4 GB. This was fine for a while but just wasn’t enough eventually.
64 bit is way more common now, which lets us use native values of up to 2^64, or 18 quintillion. RAM is capped by factors other than the number of memory addresses. 64-bit is great for things like IP addresses; 18 quintillion is really plenty for the foreseeable future.
128 bit would let us use native values of up to 2^128, or 10^39. We have no use for numbers this big. You could assign a unique ID to every star in the visible universe and only use 0.000000000000001% of the values available to you.
You’re much better off designing a 64-bit processor that’s half the size or draws half the power than designing a 128-bit processor.
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