Partitioning System drive iMac

Question

I want to partition my system hard drive
1) System OSX
2) Libraries Aperture, iTunes, ...
But I first want to know
1) Does partitioning slows down your drive speed (read/write) or working speed
2) most important! Can I ignore ownership on the 2nd partition?
I suppose it is best to start from scratch, format and partition the hard drive and then install system.
Than for the Aperture of Iphoto library, do I only need to copy the library file, or if any other information saved elsewhere?

Answer 1

Your trying to do this to solve a performance issue right?
Window users do this because Windows becomes defragmented over time and to shorted the auto-defrag process it's only done on the C: partition where the OS and programs reside, files being on the D partition.
OS X has auto-defrag on the fly (under 2GB) and thus suffers virtually little performance loss in that regard.
But there is something rather easy you can do to increase drive performance, also get a optional boot drive in the process.
1: Your going to need a external powered Firewire 800 (preferred, USB will do) equal too or larger (not too much) than your internal boot drive size. Format this external drive HFS+ Journaled in Disk Utility. (ignore TimeMachine if it appears, you use another drive for that and disconnect for this purpose)
2: Download a (donations accepted but otherwise free to use) copy of Carbon Copy Cloner and clone your entire (no bootcamp or filevault) OS X boot drive to the external drive. Disk Utility > Repair Permissions.
3: Hold option key and reboot the computer, select the clone to boot from and Disk Utility > Repair Permissions. Check out the clone very well, your going to need to make sure it's working right (just in case)
4: Now use CCC to clone the external drive onto your OS X boot drive and repeat the Repair Permisisons on both.
5: Once that's done, download a free copy of OnyX and run ALL the maintenance and cleaning aspects and reboot, both booted from the clone and the internal hard drive.
http://www.titanium.free.fr/
What cloning back and forth does is defragments the boot drive, writes the root folders and files in alphabetical order.
Applications, Library, System, Users
So the Applications get written to the hot band (the fastest part of the drive), followed by the System.
Users is written last where there is the most drive space available to expand and contract without slowing down Applicaitons or System.
What OnyX does is cleans out all the cache files, spotlight index etc., so those caches can rebuild with the new locations of your files. It also does other cleaning as well.
After this you should have as fast as possible hard drive also a external drive to option boot from in case your internal hard drive dies.
If your having specific performance issues, like slow web browsing etc., please let us know because 10.6.8 update did some things, or there might be a program that is actually causing your issues that we can resolve.