With modern kernels, and technology like UDEV, the kernel largely configures itself; it is simply a matter of comparing your available modules to the hardware, and seeing what clicks.
That said, the easiest way to minimize this (and your boot times) is to rebuild your kernel with all of your static hardware built in, and using as few modules as possible. Generally this will greatly increase your overall responsiveness, and will theoretically drop the hardware detection times to zero.
That said, changing your hard disk and amount of RAM is not going to cause the kernel to do anything differently then it was previously, as the kernel does not load specific drivers for those types of devices. Devices that need dedicated modules are things like sound cards, video cards, expansion cards, etc, etc. So there is really nothing you need to do kernel-wise in that situation (other than perhaps recompile the kernel with large memory support, if you got multiple GBs of RAM).
Last edited by MS3FGX; 09-27-2007 at 02:33 AM.