On 8/21/06, Stefan G. Weichinger <[EMAIL PROTECTED]> wrote:
Acer TM 634 P4-M 1.8GHz (cpu family : 15, model : 2) 512 MB RAM 30 GB 5200 rpm HDD
It's all relative. I have a 2.1Ghz Core Duo with 2G of RAM and a 160Gb HD, so *I* would consider your laptop, um, "underpowered". :-) But I also run with -Os. The fact is that some things will run slightly faster at -Os than -O2, and some things will be slightly slower. The same applies comparing -O3 to -O2, or -O3 to -Os; it all depends on what you are doing at the moment. So you should not assume that -O3 is faster for some random task just because it is "more optimized". It simply makes different trade-offs than -O2 or -Os, and because of the way CPUs and caches work these days, those trade-offs may help or hurt a particular segment of code. FYI, in all of the tests I did, the performance was within 10% of the median. The real deciding factor for me now is that -Os seems to take much less time and memory to compile than -O2 or -O3. And being a ~arch user, time-to-compile is a nice thing to reduce. -Richard -- gentoo-user@gentoo.org mailing list
