Happy New Year Everyone!!

I just set up my new computer using the following components:

MOBO: Asus P5B Deluxe-WIFI
CPU: Intel Core 2 Duo 6700 (not overclocked...yet)
MEMORY: 2GB Corsair Twin2x2048-8500C5 memory (2 DIMMS)
HARD DRIVE(s): 2 - Western Digital 320GB 16MB Cache/300MB's SATA Hard Drives
VIDEO CARD: BFG GeForce 8800GTX 768MB GDDR3
SOUND CARD: Creative SoundBlaster X-FI Fatality Extreme Gamer

The last computer I set up, I was using IDE hard drives. Using SATA drives is brand new to me and I've got a few questions. I've got one SATA drive set up as a MASTER (for the OS) and the other will be a SLAVE (to store info - pics / music / downloads / ect).

I have an option in the BIOS to select IDE CONFIGURATION. The options I have under IDE CONFIGURATION are as follows:

SATA CONFIGURATION (already set it to ENHANCED)
CONFIGURE SATA AS: (I have the following three to select from)
IDE / RAID / AHCI

I don't plan to use RAID right now. I'm wondering how I should configure my SATA drives. I want to have the best possible performance with these drives. Is there any performance increase by selecting AHCI?? Is selecting IDE just fine??

Are there any web sites that can help me understand the benefits, if any, using my SATA hard drives as AHCI instead of IDE and the proper way to configure the SATA drives as AHCI??

Any help is greatly appreciated