# how to tell if a em64t cpu is NUMA[solved]

## chris200x9

Hi, I have a Q6600 cpu and I am wondering how I can tell if I should use NUMA memory in my kernel configuration. By researching this topic I've found only multi-cpu are NUMA (don't know if my information is accurate), and seeing as the Q6600 is basically two E6600 stuck together I do not know what to do. On a side note if I just check this option will it do anything to *hurt* my system?Last edited by chris200x9 on Wed Jul 16, 2008 9:36 pm; edited 1 time in total

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## danomac

I could be mistaken, but I'm fairly certain that NUMA is on server processors (itanium, opteron) and not workstation/desktop processors.

A Q6600 won't have it.

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## chris200x9

ok, thanx

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## Dominique_71

I guess that 

```
cat /proc/cpuinfo
```

can tell me that. Can you confirm or not this?

I ask this because I have a AMD Phenom(tm) 9600, and cat /proc/cpuinfo doesn't show anithing about numa but the help screen into make menuconfig tell that numa must be enabled for a k8 processor, and the phenom is a k8 processor. So, i am sure of nothing.

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## gimpel

 *Dominique_71 wrote:*   

> I ask this because I have a AMD Phenom(tm) 9600, and cat /proc/cpuinfo doesn't show anithing about numa but the help screen into make menuconfig tell that numa must be enabled for a k8 processor, and the phenom is a k8 processor. So, i am sure of nothing.

 

Hey Dominique_71  :Smile: 

That help is indeed irritating. NUMA is for multi-processor systems, each processor can have multiple cores. In other words, a dual/quad-core processor is still ONE single processor. So as long you only have one, NUMA support in the kernel is quite useless.

See http://developer.amd.com/Pages/810200618_7.aspx

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## Dominique_71

Thank you gimpel   :Very Happy: 

Now, that make sens. Very informative link btw.

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## gentoo_ram

NUMA support is for large servers where memory and CPU could be separated by relatively slow busses.  The only servers I've heard of that would need NUMA would be large HP servers with Alpha or Itanium chips.  We're talking servers that support 32-64 processors and cost many hundreds of thousands of dollars.   I'm guessing IBM might have those as well, but I'm not aware of them.

The reason why they are NUMA is because "CPU modules" have memory and 4 processors on them.  Modules are separated by a switch/bus architecture.  The memory close to your CPUs are relatively faster than the memory on other modules.

Believe me, if you have NUMA you would know about it.  If you're not sure, you don't have it.  No "PC" class machines have this issue.

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