# Do you have a 64bit cpu maybe you dont know it

## kristian aka unsolo

Intel 8xx and 6xx 775 series have x86_64 aka 64bit or amd64 or em64t or i32e 

All intel XEONS with 800MHZ FSB is also x86_64

To take advantage of this you should 

Use the amd64 livecd's and amd64 guide when installing

example /etc/make.conf

```

CHOST="x86_64-pc-linux-gnu"

#CFLAGS="-O3 -march=nocona -pipe -ffast-math -mfpmath=sse,387" 

CFLAGS="-O2 -march=nocona -pipe " 

USE"-3DNow"
```

you should also activate hyperthreading in your kernels as the x86_64 version is a lot better than the old one

also ACCEPT_KEYWORDS="~amd64" in case you wonder.

join #gentoo-amd64 at freenode for further help

I have been running gentoo on x86_64 intel xeons since september 2004 and i can ashure you a lot of things work

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## adaptr

 *Quote:*   

> Intel 8xx and 6xx 775 series have x86_64 aka 64bit

 

Are you sure about this?

Intel Pentium-4s that support emt64 instructions have 64bit memory support - they are not 64bit processors.

That's what the emt stands for - Extended Memory Technology.

So far, only Intel Itaniums and AMD64 cpu's in 64bit mode are true 64bit CPU's

And, of course, all DEC/Compaq Alpha's and MIPS processors - but then, they have been 64bit for years.

And while it is true that for the x86 platform the move from 32 to 64bit memory will make the biggest impact - moving from 32bit to 64bit instructions would break the x86 compatibility - that's not what you say; they are not 64bit processors.

 *Quote:*   

> also ACCEPT_KEYWORDS="~amd64" in case you wonder.

 

I don't, actually - I would much prefer to go with the stable amd64 branch, seeing as you say later on:

 *Quote:*   

> i can ashure you a lot of things work

 

I would like to see "everything" work before committing myself.

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## kristian aka unsolo

Ok i can agree with the fact that its not a 100% 64 bit as they support x86

However the x86_64 is adopted from amd64 processors so i not only guess when i say they can run without multilib with only lib(64) which is quite hard unless the entire execution process is in 64bit or emulates 64 bit. the latteral would be insanely slower than x86 which it is not.

And regarding which processors i am 99% shure its according to intels own pages.

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## projectle

All of Intel's 64-bit processors blow monkey turds. 

Take a look at performance comparisons of the Intel 64-bit processors (or their dual core for that matter) vs the Athlon64 or the Opteron in the single or dual core varieties.

Intel had it for a long time, although like Microsoft, they took too much of the market, felt comfortable and in turn let their quality and products slip until someone else could come along and a** rape them from behind.

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## adaptr

That's... not how I would have put it  :Wink: 

But it's out now, so let's run with it.

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## kristian aka unsolo

It still pumps some more in x86_64 mode than in x86 mode

Some people might have a reason for haiving this 

so why not just let them have these cpus and happy that they run gentoo ?

And please refer to linux not windows benchmarks on perfomance comparison also make shure its only on x86_64 

not some ia32 running on x86_64

lets say HPL for instance

High performance linpack benchmark used for top500.org

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## projectle

I said nothing about Microsoft benchmarks. I merely said that Intel got too big for their own good. 

If you are saying that Intel's D or EM64T line products are even in the same league as the AMD Products, then your logic and thought processes are 95% craptastic, 5% craptacular.

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## adaptr

Then I'm sure you wouldn't mind telling us what actual facts you base this entertaining yet vulgar assessment on, would you ?

Cite references and source material, please.

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## markkuk

 *adaptr wrote:*   

> Intel Pentium-4s that support emt64 instructions have 64bit memory support - they are not 64bit processors.

 They are just as much 64-bit processors as AMD64 chips, because they support the same extended instruction set.

If you have doubts, see the Intel 64-bit Extension Technology Software Developer's Guide Volume 1 and 64-bit Extension Technology Software Developer's Guide Volume 2, and compare them with the AMD64 docs

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## kristian aka unsolo

your ignorance was so great that i didnt even have to answer my self

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## augury

lshw -C cpu

intel 640

```

  *-cpu                   

       product: Intel(R) Pentium(R) 4 CPU 3.20GHz

       vendor: Intel Corp.

       physical id: 1

       bus info: cpu@0

       version: 15.4.3

       serial: 0000-0F43-0000-0000-0000-0000

       size: 18EHz

       width: 64 bits

       capabilities: fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe x86-64 pni monitor ds_cpl est cid cx16 xtpr

       configuration: id=0

     *-logicalcpu:0

          description: Logical CPU

          physical id: 0.1

          width: 64 bits

          capabilities: logical

     *-logicalcpu:1

          description: Logical CPU

          physical id: 0.2

          width: 64 bits

          capabilities: logical

```

intel 3.2ghz p4-c

```

 *-cpu                   

       description: CPU

       product: Intel(R) Pentium(R) 4 CPU 3.20GHz

       vendor: Intel Corp.

       physical id: 4

       bus info: cpu@0

       version: 15.2.9

       slot: CPU 1

       size: 3200MHz

       capacity: 3600MHz

       width: 32 bits

       clock: 200MHz

       capabilities: fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid xtpr cpufreq

       configuration: id=0

     *-logicalcpu:0

          description: Logical CPU

          physical id: 0.1

          width: 32 bits

          capabilities: logical

     *-logicalcpu:1

          description: Logical CPU

          physical id: 0.2

          width: 32 bits

          capabilities: logical

```

im wondering if -m64 and associated flags are needed or if nocona takes care of all of this.

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## bollucks

You need the "lm" flag which means long mode ie 64 bit.

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## julot

The 6XX series of P4 and the newcomer celeron, 326 and so on, will support x86_64.

But you are wrong of using 3dnow, even sse2, sse1,  because are 32 bits based instructions.

In this moment GCC are not optimised for the complete architecture and thus is not desirable to mix the 32 and 64 bits instructions,  (let the longhorn programmers do that kind of rubbish, The AMD X_64 set already have sse2 and sse 64 bits counterparts so it is NOT needed to include:

 *Quote:*   

> 
> 
> USE"-3DNow"
> 
> 

 

So my Make.conf for the opterons is:

 *Quote:*   

> 
> 
> CFLAGS="-march=k8 -O2 -pipe -fomit-frame-pointers"
> 
> #CFLAGS="-march=k8 -O2 -pipe"
> ...

 

And it is pretty stable, so the intel counterpart must be:

 *Quote:*   

> 
> 
> CFLAGS="-march=nocona -O2 -pipe -fomit-frame-pointer"
> 
> CHOST="x86_64-pc-linux-gnu"
> ...

 

For a server and for games/workstation consider this:

 *Quote:*   

> 
> 
> #Bloddy conservative
> 
> CFLAGS="-march=nocona -O2 -pipe"
> ...

 

Compare the p4 with the following of my opterons:

 *Quote:*   

> 
> 
> lshw -C cpu
> 
>   *-cpu:0
> ...

 

So I believe that in a pure x64 binaries, it is compatible to AMD counterparts,  but as I said so,  EVADE sse, sse2, sse3, and 3dNow and 3dnowext, use it only if you use 32 bits compatibility mode of the processor.   

Cheers.

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