My Inspiron 17R has no RAID option in the BIOS. I believe to access the Intel RAID settings it is necessary to have a mSATA drive installed (which I do not have installed at this time). When a mSATA drive is installed it seems that the acceleration option (mSATA SSD caching) may be enabled in the BIOS, after which you can also do some RAID stuff.
I ordered a nice mSATA drive to install in my 17R to see if this enables the options I am looking for… I would have liked to just use the mSATA drive out of my Lenovo X220 but I don’t care to disassemble it again to remove it. Thankfully the Dell has EASY access to the mSATA port
Once my mSATA drive arrives on Wednesday I hope to be able to RAID-0 stripe my two 480GB Vertex 3 SSDs into one gargantuan volume I understand the failure risks inherent to RAID0 but for my purposes this in not particularly an issue.
Will post more once the new mSATA drive arrives, until then here are some helpful posts and forum threads on the topic!