Question

We have 32 and 64 bit processors why do we not use 128 bit processors?

Answer 1

Hello,

It is simply because there is no need for 128-bit processors. From a operating system standpoint a 32-bit operating system will work up to \(4GB\) RAM \((2^{32}~bytes = 4GB)\). When a operating system is 64-bit we can we have RAM that goes up to \(2^{64}~bytes\) and thus when talking of 128-bit processor we still have not reached a limit of having \(2^{128}~bytes\). We do not require a processor with that specification, practically speaking. If a the processor is 128-bit then the registry can accept 128-bit data, and can handle up to \(2^{128}\) bytes of RAM. So the main reason is the lack of need for 128-bit processors.

Peace.

Answer 2

oh wait why base of two?

Answer 3

That is due to binary.

Answer 4

I see thank you :)

Answer 5

You are welcome.

Answer 6

I don't understood that ,you said "32-bit OS can have 4GB of RAM not more than this." My question is. "why so?"

Answer 7

@MIT_NARIA

32-bit operating systems can have 4GB of RAM and not more, due to limits on address space (mathematically) or physical limits due to the pins on a RAM card. On 32-bit Windows RAM is limited to generally address space, and for most systems is limited to \(3.4GB\).

Mathematically:
\[2^{32 − 1} = 4294967295 = 4 GiB − 1 \]
So \(4GB\) is the theoretical maximum, however practically is another story.