# switch AMD X2 -> Intel i3/i5

## LukynZ

I have gentoo compiled for AMD with native set and I want to switch to Intel (i5 or i3). There can be potentional problems as there is no 3dnow etc. Does anybody tried to use it or recompilation/build entire new system is really needed...? (of course kernel will be set for intel platform)

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## Veldrin

I tried to run (by mistake) core2 code on k10/barcelona.

At least that way (intel code on amd) works fine, until you start to use multimedia applications (browsers, video/music player et all) which use optimized ssse3 or 3dnow code. 

So a complete rebuild might not be necessary, but it is the easiest way.

V.

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## gentoo_ram

I recently did a switch from AMD to Intel.  It was definitely a pain.  Even my AMD-optimzed gcc and binutils would crash on my Intel system.  I ended up using the Gentoo tinderbox to download binary versions of gcc and binutils packages and then was eventually able to get the system recompiled.  Start with 'emerge -e system' and once that is done you can branch out to other packages as issues come up.  And at some point you will probably need to rebuild your kernel.  You might want to do that first before you move to Intel.  Make sure your kernel has all the drivers already compiled for the system you are moving to.  Otherwise, you will need to start your new system from an Install Disk and go from there.

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## depontius

Seems to me that this might be done by 2 recompilations:

Prior to the move, recompile your entire system with a generic x86_64 target.

Move the system to the new CPU, and then recompile again to the Intel CoreI5 target.

The first recompilation is simply to get stuff that will run on either AMD or Intel CPUs, and the second is to optimize it for the new CPU.

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## Ant P.

You don't need to recompile the entire system for -march=generic, just the @system set should be enough.

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## depontius

Good point.  I also meant to add to my post that you can decide if it's easier to just reinstall.

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## LukynZ

thanks for tips....I bought i5 and I'm going to configure kernel for intel. I tried emerge system for generic, however, probably thanks to flags, it select a lot of from normal world, so...

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## LukynZ

Ok....booted from kernel for amd 'cause I forgot to change it in grub.conf

ok, xorg and kdm stars

ok, login into the kde, works, kde works, sound works...all works...except cpufreq scaling

and now a general question - does anybody have some heroin, because I can't understand this

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## depontius

Takes different drivers.  Typically for AMD you need powernow_k8.  Right now for Intel CoreI7 I'm using acpi_cpufreq.

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## LukynZ

yes cpu scheduler didn't work, but others no problem...it has same net driver, sound driver too

now I'm at intel kernel and scheduler works (acpi too)

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