Recent refining to make things faster... but need some help

[Brazil]

I was just reading the forums to see what people to to fine tune their systems, and recently have added some cflag options and have been trying prelinking...

Question about my new cflag options:
I understand that previous things I have installed have not been compiled with the new flags, but should I redo everything now, or should I just let it get better over time? This is gentoo, so I'm updating something everyday. Can I do an "emerge system" and "emerge world" after I have installed everything? Will that be a pain because config files will most likely have to be changed again?

Question about prelinking:
I have a nvidia card, and there is the issue that you can't prelink with the nvidia opengl library. So there is a tip on the forums that says to do "opengl-update xfree" then prelink. After I prelink, do I then want to do "opengl-update nvidia" and go back to using the nvidia driver? I don't understand why I have to prelink everything. Can you prelink somethings and not try to prelink everything... I understand that it has errors and says it can't prelink everything when I run the command, but why do I have to do the "opengl-update" trick? Isn't there a way to just skip a library or why wouldn't the prelink just move on? Am I missing some underlining concept?

One more question about prelinking:
In make.conf I made sure I have "prelink" in my FUNCTIONS variable, but what does that do? Should I run prelink once in a while or after every time I install or update something?

Last question:
Any other suggestions you have done to increase performance all-around?

-Brazil

[CoronaLover]

for prelink to work it needs to prelink the binary file and all of libs the bin is linked against (to see the libs run ldd /usr/bin/foo).
example: Qt is linked agains libGL.so but nvidia's libGL.so can't be prelinked so you use the opengl-update xfree and prelink your system, thus you get better performance. if you want to run a game or a 3d app you opengl-update nvidia and run it to get good 3d performance.

[Brazil]

Is there some reason no answers my questions? Atleast tell me if they are lame... I didn't think they were...

!!!!!

[snipingkills]

Well i dont know anything about the prelinking, but if you really want to recompile everything with your new CFLAGS, I think the option to do so is emerge -e world. I'm not an expert, so I could be wrong.

[balk]

Is there some reason no answers my questions? Atleast tell me if they are lame... I didn't think they were...

!!!!!

they are not too lame. No answers can mean "too difficult to answer" or "takes too much time to answer" or "just slipped away before a guru sees the topic" (not that I'm a guru or extremely smart .....)

If you do not mind letting your PC compiling a _long_ time, do a 'emerge -e world', this will recompile almost everything you ever installed on your PC (except glibc and the kernel, if I remember right). As you can imagine, this will take some time, especially of you have kde, mozilla and openoffice installed.

Altough I have a Nvidia card installed, I never experienced problems with prelinking (or did not notice problems ). Did you take a look at this guide?
As far as I understand it, prelinking puts dynamically linked libraries into the binaries so they will run smoother once started.