Will there ever be a need for a 128-bit CPU in your computer?

[FordGT90Concept]

2^64 = 18,446,744,073,709,551,616 bytes or 16 exa-binary-bytes (EiB) or 18 exabytes (EB).
2^128 = 340,282,366,920,938,463,463,374,607,431,770,000,000 bytes; no SI prefix exists to describe a number that large. It could coequally be said as 340 billion, billion, billion, billion bytes.

 

[Basard]

I don't see why we are even using more than 640k RAM.... Bill Gates deemed it to be enough.

 

[yogurt_21]

2^64 = 18,446,744,073,709,551,616 bytes or 16 exa-binary-bytes (EiB) or 18 exabytes (EB).
2^128 = 340,282,366,920,938,463,463,374,607,431,770,000,000 bytes; no SI prefix exists to describe a number that large. It could coequally be said as 340 billion, billion, billion, billion bytes.

or 340 trillion yottabytes. or if you could stack terms 340 tera-yottabytes

Essentially as out of reach today in disk storage terms as a petabyte was in 1980. So yeah we're talking a long time before 128-bit becomes useful for servers. Still not sure for whatever desktops will be in 50 years.

 

[xorbe]

You are missing something. 32 bit can address ~4GB of RAM while 64 bit can ... well! double that number 32 times i.e. 16 ExaBytes.

1 exabyte = 1 000 000 000 gigabytes

32-bit mode can access more than 4GB with certain modes. 64-bit mode can't actually use full 64-bit addresses, it's something less. It's more like 36-bit vs 52-bit. This is to keep page tables and depth at reasonable sizes. On x86 this is handled by a hard-coded page table walker. On the defunct Alpha arch, it was software (pal code) defined.

Current x86 chips already have 128 and 256 bit multimedia instructions, don't they? It's just not extended to the whole instruction set, or addressing modes. They don't even use 64-bit addressing just yet, there is still room to grow for quite a while.

 

[Atomic77]

Terrabytes Petabytes Zetabytes it could go on and on.

 

[R-T-B]

32-bit mode can access more than 4GB with certain modes.

Technically, it can't. It can however, access memory above the 4GB address space with PAE. But it can't use more than 4GBs at once per process (ie, at a given moment).

Just nitpicking. You are pretty much spot on.

Terrabytes Petabytes Zetabytes it could go on and on.

Yes, those numbers exist, but there comes a point where they are simply too big. I don't remember where it starts but at some point beyond Petabytes short of going quantum we simply can't do it, because there aren't enough atoms available on the entire planet.

 

[FordGT90Concept]

Yotta was added to SI prefixes in 1991. No doubt more prefixes will be added to describe such a large number but as of right now, they don't exist. 340 quintillion septillion would likely be the most accurate way to phrase it now.

 

[AlwaysHope]

Here's one area that will push the limits of 64bit computing.
I predict that every single byte of data will have unparalleled levels of security associated with it (and all that involves!) will become MUCH more complex than any of us could ever imagine today. This alone could very will chew up a LOT of memory space for those who like 'on the fly' constant encryption like with cloud computing, software as a service, etc.. If we think 512 bit support is pretty good today... then I expect that to more than quadruple, if not then 10 fold or more in the coming years...

 

[lilhasselhoffer]

Technically, it can't. It can however, access memory above the 4GB address space with PAE. But it can't use more than 4GBs at once per process (ie, at a given moment).

Just nitpicking. You are pretty much spot on.



Yes, those numbers exist, but there comes a point where they are simply too big. I don't remember where it starts but at some point beyond Petabytes short of going quantum we simply can't do it, because there aren't enough atoms available on the entire planet.

Thought I'd expound on that. The Earth is 27.7% Silicon by mass: http://hyperphysics.phy-astr.gsu.edu/hbase/tables/elabund.html
The mass of a single atom of silicon is 28.085 amu.
The mass of earth is 5.972*10^24 kg.
The mass of Silicon is therefore 1.654*10^24 kg.
The amount of silicon atoms on earth is therefore 1.654*10^24 kg / 4.6*10^-26 = 3.5957*10^49 atoms.

Now, the fun:
If you only needed 4 silicon atoms per memory cells, that would mean about 1*10^49 memory cells could be produced. With the above value of 2^128 being 340*10^36, that would mean that if every atom of silicon was used in CPUs there's be only about 1*10^11 memory chips available.


In short, if we continue to produce chips out of silicon we won't be running out any time soon. You can alter my assumptions, but that's where computing is currently traveling.

 

[FordGT90Concept]

And don't forget the virtually unlimited quantities in...

 

[DeathtoGnomes]

Well after reading a bunch of posts I can say there are a lot of naysayers to needing 128-bit and beyond. IMHO, We really do need hit the 256-, or even the 512- bit wide registers, I mean how else are we ever going to get the transporters built and working? The way things look now we cant even have a 64-bit memory controller! Bottlenecks-R-US!! Come-on you alien assholes share that knowledge!

 

[R-T-B]

Thought I'd expound on that. The Earth is 27.7% Silicon by mass: http://hyperphysics.phy-astr.gsu.edu/hbase/tables/elabund.html
The mass of a single atom of silicon is 28.085 amu.
The mass of earth is 5.972*10^24 kg.
The mass of Silicon is therefore 1.654*10^24 kg.
The amount of silicon atoms on earth is therefore 1.654*10^24 kg / 4.6*10^-26 = 3.5957*10^49 atoms.

Now, the fun:
If you only needed 4 silicon atoms per memory cells, that would mean about 1*10^49 memory cells could be produced. With the above value of 2^128 being 340*10^36, that would mean that if every atom of silicon was used in CPUs there's be only about 1*10^11 memory chips available.

Thanks for the scientific backup. Still, consuming your entire planet plus other parts of space to make a single 128-bit addressable memory chip strikes me as extremely environmentally unfriendly.

Actually, it wouldn't even surprise me if that's the premise with which aliens will invade us. "You are now memory chip. Nom nom"

 

[DeathtoGnomes]

Thanks for the scientific backup. Still, consuming your entire planet plus other parts of space to make a single 128-bit addressable memory chip strikes me as extremely environmentally unfriendly.

Actually, it wouldn't even surprise me if that's the premise with which aliens will invade us. "You are now memory chip. Nom nom"

I think it was "so you want to be a wizard" book series that references a planet of pure silicone, with an attitude...

but...

dropping chips can be environmentally unfriendly too.

 

[qubit]

Technically, it can't. It can however, access memory above the 4GB address space with PAE. But it can't use more than 4GBs at once per process (ie, at a given moment).

Just nitpicking. You are pretty much spot on.

This is called paged memory access and is something they did on 8-bit computers 30 years ago with their tiddly 64K RAM limit. My BBC Master computer did this for a "massive" total of 128K RAM.

It's quite ironic seeing the same technique being used in a modern computer that can address gigabytes of RAM today.