Quickie on installing via a raid controller.

My current system is set up like so

C Drive has a dual boot running windows and ubuntu (40gb)
D Drive is a 250gb drive managing all my media

I then have two 80gb drives plugged into a raid controller. (they are not set up in a mirror or stripe array just using the raid controller cos i ran out of ide slots.)
On one drive I keep all my important docs (formatted in fat so i can access from both windows and ubuntu) and the other is used to back up all the important data i have on the other three drives.

I want to install a couple of other distros to have a play around and see what there like.

I was planning on partitioning my second raid drive that i use for backing up to give me some space to do this. Will grub recognise this partition if its running via a raid contoller or will I have to install on one of the hd plugged directly into the ide slots.

Thanks for any advice.