Help on Sata with Raid 0

I finally rebuilt my computer with raid0 using 2 Sata 3Gb/s Harddrives. After setting up my HDD and instaling Windows Vista, I ran benchmark on my HDD performance. The performance is not close to what I was expecting. The read/write performance seem to be the same as non-raid. I also tried copying 1 file (1gig file) from one location to another, and it takes about 35 seconds. This is also about the same as my other computer with non-raid. I also do not notice significant improvement in starting up windows or applications.
Whats' the performance I should expect from raid0? and how long does it take to copy a 1 gig file? I just don't see much improvement between raid0 and non-raid.

Since you installed Vista yourself, you probably know how to image off the OS partition and restore it. Now that Vista SP 1 RC is out, you could download and install it. It's supposed to have performance improvements. At least that way, you'll now if the performance is ever going to get better under Raid0.