Well if you don't have a RAID controller you don't have the Ctrl-G prompt. If you want to use the onboard SATA ESRT2 RAID you need to enable it in BIOS first, and you'll get a Ctrl-E prompt. See the demo for details: http://www.intel.com/support/motherboards/server/sb/CS-032119.htm
How slow is that? What's the exact symptom?
Yes RAID 10 could be faster than RAID 1, but you may want to find the real bottleneck first. Also, make sure you use HDDs from the Tested memory and hardware list. Also, SATA drives could be very sensitive to vibration.