# Installation on Intel Q6600 Core 2 Quad

## Fracoon

Hi@all

i just got my new Intel Q6600 Core 2 Quad with 4Gb of RAM... and now i have some questions.

I will install gentoo on this machine and use it with xen. But first of all i want to know how to configure the "base" system.

First Question : What live cd should i use? I want a 64bit system.

Second Question : What settings should be in make.conf? For the quad core and for XEN? I ask this because i dont want to build the system more than once =)

So any answers would be great.. 

thx...

----------

## phsdv

For a 64bit install you could use 

```
install-amd64-minimal-2007.0.iso
```

 or 

```
livecd-amd64-installer-2007.0.iso
```

It sounds strange but you need amd64 for your intel core2!

Your make.conf could look like this:

```
WARNING this is not a complete make.conf, check with the docs for more details

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

CFLAGS="${CFLAGS} -mno-tls-direct-seg-refs"     # xen

CXXFLAGS="${CFLAGS}"

CHOST="x86_64-pc-linux-gnu"

FEATURES="sandbox usersandbox distfiles parallel-fetch fixpackages"

MAKEOPTS="-j8"   # 8 for quad core

USE="nptl nptlonly"                                # system

USE="${USE} mmx mmxext sse sse2 ssse3"                  # processor

USE="${USE} smp"                                  # at least for gimp maybe for others later... 

# add your own use flags here...

```

I hope this helps.

----------

## Fracoon

thx alot. I will try this. 

Do you think it makes sense to do a stage 1 install?

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## phsdv

 *Fracoon wrote:*   

> Do you think it makes sense to do a stage 1 install?

 I am sorry I do not know, I only did stage3 installs so far. Which means that you have to recompile your system after the install, but with a Q6600 and -j8 it will not take too long   :Wink: 

----------

## eyoung100

See Here:

Safe Cflags for safe CFLAGS and use the amd64 handbook and iso to take full advantadge of your new system.

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## n0ns

It will take some time (especially gcc and glibc).

some packages pass to compiler to use j1.

Anyway, it will be much faster to use stage 3. As I know, there is no benefit from using stage 1, but a lot of dirty work and complications.

----------

## phsdv

I just read in the howto: ( http://gentoo-wiki.com/HOWTO_Xen_and_Gentoo ):  *Quote:*   

> Note: The '-mno-tls-direct-seg-refs' flag does not make sense on any 64bit system. For such systems you can skip the recompilation of the whole world and just recompile glibc

 So that would safe you some work. But I can confirm that including this flag does not harm...

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## Spidey

What are sandbox and usersandbox FEATURES? I mean, in the past week I had too many troubles which led me to use -sandbox in FEATURES...

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## likewhoa

 *Spidey wrote:*   

> What are sandbox and usersandbox FEATURES? I mean, in the past week I had too many troubles which led me to use -sandbox in FEATURES...

 

read the definition in /etc/make.conf.example  :Wink: 

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## DrAgOnTuX

why -j8 and not -j5 ?

i thought it was -j((number of cores) + 1)   :Question: 

----------

## PaulBredbury

 *DrAgOnTuX wrote:*   

> why -j8

 

Because some of those parallel processes may be sleeping, waiting for hard disk activity.

The -j number is just a guesstimate anyway.

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## phsdv

 *DrAgOnTuX wrote:*   

> why -j8 and not -j5 ?
> 
> i thought it was -j((number of cores) + 1)  

 Because I want to keep each core 100% busy!

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## DrAgOnTuX

ok   :Wink:  nice to know, I'm gonna buy a Q9450 if they're available

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## gm7uac

Hi 

my system is a Core2 Quad 6600, I had problems seeing the sata controller with the gentoo install CD's

Linux localhost 2.6.23-gentoo-r3 #7 SMP PREEMPT Sun Dec 16 12:27:50 GMT 2007 i686 Intel(R) Core(TM)2 Quad CPU @ 2.40GHz GenuineIntel GNU/Linux

still fine tuning... having problems emergeing gimp complains about jpeg plugins.

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## phsdv

 *phsdv wrote:*   

>  *DrAgOnTuX wrote:*   why -j8 and not -j5 ?
> 
> i thought it was -j((number of cores) + 1)   Because I want to keep each core 100% busy!

 I did some test to prove -j8 helps. I choose a kernel compile. First with -j8:

```
linux-2.6.23-gentoo-r5 # time make -j8

...(deleted compile stuff)...

Kernel: arch/x86_64/boot/bzImage is ready  (#1)

real    1m41.928s

user    5m38.618s

sys     0m52.060s

linux-2.6.23-gentoo-r5 # make clean

linux-2.6.23-gentoo-r5 # time make -j8

.... (repeated to see if cache does something)...

Kernel: arch/x86_64/boot/bzImage is ready  (#2)

real    1m40.929s

user    5m37.518s

sys     0m51.850s
```

OK pretty much the same, lets try without -j8

```
linux-2.6.23-gentoo-r5 # time make

......

real    5m22.479s

user    5m3.757s

sys     0m41.597s
```

user time is actually shorter, 5m3.757s i.s.o 5m37.518s but who cares  :Wink:  The real time you have been waiting is now 5m22.479s in stead of 1m41.928s. Lets see what -j5 is doing on my quad core:

```
linux-2.6.23-gentoo-r5 # make clean

linux-2.6.23-gentoo-r5 # time make -j5

......

real    1m40.506s

user    5m35.635s

sys     0m52.120s
```

OK, wow it is indeed faster! -j5 gives 1m40.506s and -j8 1m40.929s. It is not much, only 0.4s but to my it is enough prove that -j((number of cores) + 1) is enough!

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## Monkeh

 *phsdv wrote:*   

> OK, wow it is indeed faster! -j5 gives 1m40.506s and -j8 1m40.929s. It is not much, only 0.4s but to my it is enough prove that -j((number of cores) + 1) is enough!

 

No... It isn't. Run it again, it might well take another second. It very much depends on the software you're compiling. -j8 is good, as long as you have enough RAM.

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## phsdv

 *Monkeh wrote:*   

>  *phsdv wrote:*   OK, wow it is indeed faster! -j5 gives 1m40.506s and -j8 1m40.929s. It is not much, only 0.4s but to my it is enough prove that -j((number of cores) + 1) is enough! No... It isn't. Run it again, it might well take another second. It very much depends on the software you're compiling. -j8 is good, as long as you have enough RAM.

 Some more runs for statistics only (shown in sequence as run, with 4G ram):

```
linux # make clean && time make -j5

real    1m44.332s

user    5m30.832s

sys     0m50.933s

linux # make clean && time make -j5

real    1m38.766s

user    5m34.358s

sys     0m50.713s

linux # make clean && time make -j5

real    1m39.456s

user    5m33.525s

sys     0m50.443s
```

```
linux # make clean && time make -j8

real    1m42.260s

user    5m38.278s

sys     0m51.850s

linux # make clean && time make -j8

real    1m40.763s

user    5m38.405s

sys     0m52.037s

linux # make clean && time make -j8

real    1m40.768s

user    5m37.961s

sys     0m51.367s
```

User time is always lower with -j5 than -j8. Real time does differ, but on average -j5 is still faster. I think that with 4G I do have enough memory to do a -j8 without swapping, so that will not be the cause for a slower compile.

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