On Sat, 5 Feb 2011 15:45:08 +0000
Paul Stear <gentoo@...> wrote:

> I am currently using amd64 2 core processor but now have the chance to use 
> an intel quad 64 processor.
> This might be a silly question but is it best to do a compltly new install?

As long as you are using Gentoo 64-bit there is no need for a new
install.  The only difference is the number of cores, and perhaps
some new FPU options.

> Which chost and cflags should I use?

CHOST is the same.  No change.

CFLAGS may need to be altered.  Some Intel quads have SSE 4.1 while others
have SSE 3.  You need to check the exact processor version to find out
which is present.

Also you can set MAKEOPTS="-j5" for the quad processor.

If you are compiling your own kernel, you may want to change the
NR_CPUS configure option to 4, and if the new cpu has hyperthreading
as well, then also select SCHED_SMT.

I assume that for the previous Core2 duo you already have the multi-core
scheduler support, SCHED_MC, selected.

Beyond these small changes, nothing new is required.  Just pop the
new quad in and go.

Frank Peters