# Migrating Gentoo install from Core2Duo to Core i7 860

## jeffk

I'm transplanting a ~amd64 Gentoo server image from hardware A to hardware B:

A) Intel Core 2 Duo E8500 Wolfdale 3.16GHz LGA 775 65W Dual-Core Processor on GIGABYTE GA-EG45M-DS2H LGA 775 Intel G45

B) Intel Core i7-860 Lynnfield 2.8GHz LGA 1156 95W Quad-Core Processor on GIGABYTE GA-P55M-UD2 LGA 1156 Intel P55

My /etc/make.conf is pretty generic, any suggested CHOST or FLAGS changes for the new hardware?:

```
$ head /etc/make.conf

CFLAGS="-O2 -pipe"

CXXFLAGS="-O2 -pipe"

CHOST="x86_64-pc-linux-gnu"

MAKEOPTS=""

...
```

In addition to having time to reemerge if it will help performance. I will have some time to work with the genkernel config before migration day, initially booting the image using the Gentoo LiveCD or SystemRescue CD, I expect to find a few obvious config options in the CPU section of menuconfig.

Is there any method or tool that can help me map kernel CONFIG_foo options to detected hardware and loaded modules from a genkernel built with every module such as the LiveCD?

Thanks.

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## Randy Andy

Hi jeffk,

to find out the right CFLAGS for your new processor follow this guide:

http://en.gentoo-wiki.com/wiki/Safe_Cflags

There exist on new "tool (kernel / make option)" called "localmodconfig" to find out your requesed kernel CONFIG_foo options, i haven't tried out until now, but i mentioned it in this thread, so give it a try and let us know how it works, if you want.

https://forums.gentoo.org/viewtopic-t-804840-highlight-.html

Regards, Andy.

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