Micro-freeze/Hiccups in games on new build

Hello, I've recently built a new computer and have been tearing my hair out trying to fix this issue. What happens is during games the game will freeze for around .5 - 2 seconds, becoming unresponsive though the cursor still moves and sound and music still play. The HDD access LED is solid during this time. It will occur at specific times, say in Starcraft II just as a building completes construction, though not every time. The game runs silky-smooth the entire time otherwise, at 60 fps regardless of what else is going on.

I have three hard drives in the computer, an SSD as the system disk with Windows 7 64-bit installed on it while the majority of games are installed on a RAID0 of two Western Digital 1.5TB Caviar Blacks. I am nearly positive it has something to do with the RAID, as another game that was giving me a lot of trouble, League of Legends (would hang for 1 second during large fights, enough to entirely mess up my game), became perfectly fine after I installed it on the SSD instead of the disk array.

I have tried many things and installed all possible drivers associated with my motherboard and SATA/RAID controllers several times and nothing has entirely rid me of the problem. It was much, much worse before I disabled "Onboard SATA Controller" in the BIOS, but the problem still persists, just less consistently. Before I did that, every single time I destroyed a building in Starcraft II, or every time someone talked in Recettear, it would hang briefly. Now it is not as consistent, though it still seems that specific events trigger it.

I've contacted Western Digital about it, but they just told me to run their disk-checking program and to RMA if it turned up bad. Ran the long and short test twice and everything was fine. Outside of games the RAID performs admirably, large files read and write without a hitch. Of course, it is not the system drive, so naturally Windows performance is not likely to be affected.

This has been fairly frustrating to me, as everything else about the computer is perfectly fine, and I've built several computers for friends which have not had this issue (though none of them had RAIDs), and this is my first time building one for myself. I appreciate any advice you can offer!

I'll list a few of my components which may be the issue, as I'm still not 100% sure it's just the HDDs. If you need any more info I'd be glad to provide.

Motherboard: ASUS Rampage III Formula
SSD: Crucial RealSSD C300 64GB
HDDs: Western Digital Caviar Black WD1501FASS 1.5TB 7200 RPM x2
RAM: G.SKILL PI 6GB (3 x 2GB) 240-Pin DDR3 1600, currently clocked at 1440 MHz, 6-8-6-20 timings
CPU: Intel Core i7-950 @ 4.15 GHz (problem occurs at standard clocks as well)
GPU: EVGA GeForce GTX 470 (Fermi) 1280MB x2 (though this occurred before I got the second card as well)