Why does amd call a 64 bit cpu x86?

[melikepie]

i commonly see x86 stuff advertised on 64 bit chips, why do they do that?

but x86 is still epic! you can build a cpu in minecraft but it was 4 bit, my friend blow up ther other 4 bits

 

[DelroyMonjo]

X86 is the instruction set for the CPU. Early CPU's used 16 bit and it's moved upward since. It started out as 16 bit then moved to 32 bit and is now most commonly 64 bit instructions. Supposed to be backward compatible so you can run Win 7 on an original 8086 chip.

 

[amuffin]

x86 is instruction set..

 

[melikepie]

X86 is the instruction set for the CPU. Early CPU's used 16 bit and it's moved upward since. It started out as 16 bit then moved to 32 bit and is now most commonly 64 bit instructions. Supposed to be backward compatible so you can run Win 7 on an original 8086 chip.

ok... why in the world would sombody run windows 7 with a 8086... wikipedia said it's 16 bit with 5MHz-10MHz wow bf3 must run good on 16 cash registers (lol)

 

[amuffin]

Just because it can be run on W7

 

[gamerk316]

Because, AMD64 is simply an extension of the X86 instruction set.

 

[photonboy]

*MORE:
Actually, I've noticed Microsoft and others differentiating 32-bit vs 64-bit this way:

32bit -> x86
64bit -> x64

In reality it should be:
32bit -> x86_32
64bit -> x86_64

What happened was that even though "x86" represents the Instruction Set for most desktop CPU's, 32-bit was around so much that x32 became interchangeable with x86.

However, when x64 (64bit) cropped up many people (including Microsoft) have messed it all up.

 

[gamerk316]

*points out the X86 ISA started as a 16-bit architecture*

 

[noob2222]

Dont forget the Itanic IA 64 wich was 64 bit only and would not run on a x86_32bit os.

 

[melikepie]

Best answer selected by melikepie.

 

[$hawn]

X86 is the instruction set for the CPU. Early CPU's used 16 bit and it's moved upward since. It started out as 16 bit then moved to 32 bit and is now most commonly 64 bit instructions. Supposed to be backward compatible so you can run Win 7 on an original 8086 chip.

An 8086 WILL NOT RUN Windows 7...it has no FPU !!
u'll have to couple it with a 8087

Secondly, 8086 is 16 bits, Win7 is only available in 32/64bit versions.

Even if there was a 16bit version, i still doubt it would work, coz i think Win7 needs atleast the MMX and SSE1 instruction sets

 

[DelroyMonjo]

Well, $hawn, I did say 'supposed' to be compatible. But I'll give you props for adding useful information to the answer.