On Wed, Sep 20, 2006 at 04:25:12PM -0400, Jack Lloyd wrote:
> 
> Tomorrow my new Core 2 workstation should be arriving, and reading
> through the 2006.1 amd64 install notes and so forth, the recomended
> CFLAGS for EM64T CPUs is -march=nocona. However as that is tuned for
> 64-bit enabled Netburst rather than Conroe, I'm wondering if anyone
> had thoughts on good flags. In particular as (to the extent that I
> know anything about microarchitecture), Conroe seems closer to a K8
> than a P4, especially with regards to pipeline length and execution
> resources, I'm not sure that P4/Netburst tuning is the right thing to
> do. But the GCC docs say that -march=k8 enables 3dnow, which Intel
> chips don't have. So, right now the "seems likely" options would
> be:
> 
> -march=k8 -mno-3dnow -msse3
> -march=nocona
> -march=pentium-m -m64 [saw this suggested in the forums, seems like a bad idea]
> 

I've got a Dell XPS 700 with an E6600, and, like you, wondered what were
the "best" CFLAGS to choose. Lacking any solid directions, I went with:

CFLAGS="-march=nocona -O2 -pipe"
CHOST="x86_64-pc-linux-gnu"
CXXFLAGS="${CFLAGS}"
MAKEOPTS="-j3"

Simple, and nothing fancy.

I'm happy to say that my 2006.1 amd64 install seems to be working great.
I'm running unstable, btw, which I've been doing on my old athlon64 for
a couple years now.

I'm still tweaking my kernel options though.

P.S. It's amazing how fast a kernel builds and emerges happen on the new
Core 2.

-- 
Eric Augustus
shrike@...
-----------------
Are we on STRIKE yet?
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