Pentium 4 (Prescott): Which CFLAGS are better?

[westves]

Hi.
Could anybody say which CFLAGS for Intel Pentium 4 630 (Prescott) have better performance :

Code: Select all

32-bit profile (x86)
CHOST="i686-pc-linux-gnu"
CFLAGS="-march=prescott -O2 -pipe -fomit-frame-pointer"
CXXFLAGS="${CFLAGS}"

or

Code: Select all

64-bit profile (amd64)
CHOST="x86_64-pc-linux-gnu"
CFLAGS="-march=nocona -O2 -pipe -fomit-frame-pointer"
CXXFLAGS="${CFLAGS}"

Thanks for any advices!

[Scratalacha]

Assuming you are using gcc 4.2 or greater (I'm pretty sure about this...), you can use -march=native and GCC will choose for you.

[ShinyThings]

Well, the second option (the x86-64 one) will give you a 64bit system. The performance increase will probably be negligible unless you are doing anything scientific or perhaps statistics-related. It also comes with a few minor software issues that you may want to avoid.

That being said, I use a 64bit system, and I have no complaints.