I'm planning to connect all my hard drives to an PCIe RAID controller. Only a SATA CD/DVD writer will be connected to one of the onboard sata ports. In this scenario, do I need to switch to IDE mode since I will not be using the onboard SATA ports for the hard drives? Will this cause any performance decrease for the CD/DVD writer? Even if I were to use the onboard sata ports for my hard drives, would you still recommend IDE mode?
And can someone please explain to me what these modes are for?
AHCI or Advanced Host Controller Interface is supposed to give your HDD more performance, but many times people have shown that it either makes performance worse or not any better. I have my SATA drives configured in BIOS as [IDE] for both my SATA HDD and SATA DVD-R. RAID 0 for example is for using two HDD together in RAID, mainly both HDD each share half of the total information or data of your entire OS apps and games. The advantages are that one HDD can copy data and the other drive can write data to RAM all at the same time. One single drive can't do both at the same time.
The disadvantages are if one drive fails you lose everything because half the data is lost, you double your chances of losing everything. So yes I recommend [IDE] mode for any SATA drive. Some mobo's onboard SATA controllers don't work when theres another in the system, but this is not always true but...
I see, so I guess [RAID] mode automatically brings the features [AHCI] mode offers, right?
Thats correct, you need to install the RAID drivers if you intend to use AHCI. You can get just the AHCI drivers at Intel's website, but it won't do much for performance in most HDD. I have a very fast Raptor 10,000 RPM drive in IDE mode, tried AHCI but no difference.