Trying to use some local storage (3 x 750GB Seagate's in a Raid 5, and another random 80gb drive for the OS) on an ESX box, I decided to use the onboard raid for the Asus DSBV-DX. I had two problems, and I can thank some newsgroup posters for solving my issue(s).
Using the Default LSI controller build into the mobo (there are 6 Raid ports, they can be controlled by either the LSI or the Intel Storage Matrix) I could not create a raid 5 out of my disks, I tried everything, but in the LSI bios, it allowed me to choose Raid 5, but then gave the error of "Invalid Operation. Pls check the RAID key", so after my friend google found me this article http://vip.asus.com/forum/view.aspx?board_id=5&model=DSBV-DX&id=20080601052918421&page=1&SLanguage=en-us I realized that I had to use the Intel controller to leverage Raid 5, since the LSI doesn't support it.
Now that I have swapped the jumper over to Intel, and sucessfully configured a Raid 5 out of my drives, The ESX 3.5 Up3 install tells me that I have 3 individual drives, not the Raid 5 Single Drive it should see. Again Mr Google found me this http://vip.asus.com/forum/view.aspx?board_id=5&model=DSEB-DG&id=20080601004357890&page=1&SLanguage=en-us . So I grabbed a PCI-X ESX supported Raid controller, and now my ESX server is working again with local storage just like I wanted it.
another 20 minute job that took 6 hours...I love technology