Recommended motherboard with hardware raid for Linux
Usually, the onboard controllers are fakeraid devices, so if you're building a linux server, you'll be better off with software raid (mdX) instead.
afaik if you're planning on a hardware raid solution, you'll need a proper controller, like LSI (or variants - dell PERC/IBM ServeRaid/etc), or 3WARE - all of them are very rare onboard, and pretty expensive.