what is x86?

[Swndlr]

i get that x86 is like the whole cats pajamas and whatnot but why is it called x86 i wanna know.

[Nineshadow]

It's a family of instruction sets architectures..

 

Although it is commonly known as 32 bit.

[Speedbird]

It's the instruction set of a modern CPU. This comes from the first Intel 8086, then they released the 186, and the 286, and the 386 and so on. As they were compatible, people just started calling it x86.

[Wano97]

I don't actually know the answer myself, but here's quote from Yahoo

x86 is actually just notation for a CPU instruction set which has been used in most modern day processors. x86 actually has three different subsets: x86-16 (16-bit), x86-32 (32-bit) and x86-64 (64-bit). 

The 32-bit version of x86 became so common that eventually the term "x86" by itself was known to be the 32-bit iteration. The newer 64-bit version can be referred to as it is above, but far more often is simply called "x64", which can understandably be confusing to someone who doesn't have a lot of knowledge concerning computer hardware, as it sounds like a step backwards! 

Because of this, the 32-bit version of Vista is "x86", and the 64-bit version is "x64"

[Swndlr]

It's an instruction set.

 

Although it is commonly known as 32 bit.

so then what is 64 bit? x64?

[Volbet]

It's a instruction set used by all modern desktops and laptops, and even some tablets.

Wikipedia has a more indepth artical about it, if you want to learn more: http://en.wikipedia.org/wiki/X86

 

so then what is 64 bit? x64?

64bit is still X86. it's usually refered to as X86_64 or AMD64. 

[WinNut]

It's an instruction set for 32-bit processors. 64-bit processors are called x86_64 processors AFAIK.

[Nineshadow]

so then what is 64 bit? x64?

http://en.wikipedia.org/wiki/X86-64

X64, X86_64, AMD64

[virtualTune]

@AlwaysFSX have fun

[virtualTune]

so then what is 64 bit? x64?

x86-64

[Swndlr]

x86-64

it-it all makes sense now

[Cryptonite]

nvm it's late.

[AlwaysFSX]

@AlwaysFSX have fun

Y u do dis to me.

[LukaP]

Y u do dis to me.

cuz he lov u

[virtualTune]

cuz he lov u

exactly

[Guest]

x86 = 32bit x86-x64 (AMD64) = 64bit

[GoodBytes]

Ok I'll give it a spin:

x86 is a name which represents instruction set that the processor support. What are instruction set? To put it simply, it's a set of operation codes that the processor can execute to do stuff.

For example:

Adding with ADD. ADD will take a number it stores in its memory (one of the processor registers), and add a number to it, and stores the result somewhere.

Now, I can make GB architecture for my own GoodBytes lines of CPUs, and I decide to call add operation: GB_ADD1, and GB_ADD2, and I say that mine are better, you can use GB-ADD1 to add 1 number to something, and you can use GB_ADD2 allows you to add 2 separate numbers to something, and the way it adds is different. I believe that the design of my architecture makes thing execute faster.

In my case, this is my instruction set for my CPUs.

If you try to put GB_ADD1 and GB-ADD2 on a Intel processor which uses x86 instruction set, well it won't work. The processor won't know what these are.

That is why, you can't run a PhotoShop or Counter Strike or Steam, on an ARM based processor like what is in your smartphone. The processor won't know what these x86 instruction are (and that is beside Windows API and libraries, which make the program not run on anything else beside Windows, the same story for Linux, and MacOS, or why iOS apps can't run on Android despite both using ARM based processors. In such case an emulator is needed. Hence, why if you want to play console games on your PC, you need a emulator, as you need to emulate/translate the OS APIs and also the processor instructions.

So, "x86" is just a name. It could have been called Swndlr. And than we would say that Intel processors are Swndlr architecture. Sadly, that is not the case.

The reason why we refer "instruction set" as "CPU architecture", is because the circuitry goes with it, and requirements in the design of the processor.

Remember that "ADD" is a name at a human level, what the processor sees is: 100111 (not actual fact, just an example of binary numbers), and that engages the circuitry of the processor, which makes the magic happen in doing the addition.

This is also why, AMD processors, are similar to Intel CPUs. In order to support x86 instructions set, AMD have no choice to have the same architecture as Intel.

Now, what is 32-bit and 64-bit.

It's the length of instructions that the processor supports. That is why, at a text book and general level, a 32-bit processor can only access 4GB of RAM, and not more. It physically can't

The last address space of the memory is: 11111111111111111111111111111111. That is 32 digit long or 32-bit long.

64-bit, means that there is 64 slots for 1's and 0's that can be placed. So, it can access more memory.

Now, in reality 64-bit is more than that. It support new operation code in the instruction set to do things faster, because now we have the resources for them. They are based on creation made from other 64-bit processors on the market (64-bit processors with their own instruction sets, like my GB architecture talked about on my example could be for a 128-bit processor, and let's assume it's amazingly powerful and awesome, Intel might be interested in implemented something like I did, the day we switch to 128-bit processors. Why not now? Well, my operation code is especially long where it won't allow it to fit in anyway on a 64-bit processor.

So then, what is x64?

It is a bit of a mess, x64 is the unofficial name used to say that the processor support 64-bit long instruction and instruction set develop my AMD, which Intel uses in their CPU.

The real name is AMD64. So, technically, Intel should say: "This Core i7 processor, supports AMD64", but obviously they won't, as its called "AMD". So they just say "64-bit instruction set supported". That is why, if you dig inside Windows files or registry, you'll see many entries with "AMD64" within names, even is no AMD product ever touched your system.

But, because AMD work is not a standalone instruction set/architecture, it's an addon only, it can't run by itself standalone. It is dependent on x86.

So, our processors that we use in our laptops and desktops, is refer as AMD64 or x86-64.

AMD pays license fee for Intel x86 architecture.

And Intel pays AMD a license fee for AMD64 architecture add-on.

I hope this makes it more clear.

[SubTract]

I always Giggle a little bit when I'm installing Linux on an intel CPU and it's constantly referring to AMD64.

And back in the days on AMD hardware when it said Intel x86