Yes, you will lose all info and will have to recreate. Plus it's not faster AT ALL unless you're spending over $500 on a card. Really the only reason to get a RAID card is 1) You're in love with RAID5 or 6 etc. or, 2) you want to connect more than 6 HDDs. Like I say, unless you wanna spend $700 or $800 on a "good" card. And even then the speed will only be slightly better.