Hm.. a good question, because i don't remember, and Device Manager didnt provide me any valuable info.
However, when i went to check it via AIDA64, it says that the same. Anyway, it says that i have
"Drive #1 - AMD 2X2 Mirror/RAID1 (3725 GB)"
and
"Drive #2 - WDC WD20EARS-00J2GB0 (1863 GB)"
That surprises me, because i have to have only 2*2 Raid10 and that's it.