In my home file server I have a single Promise FastTrak SX4100 configured with 4 WDRE 400Gb drives in a Promise SuperSwap 4100 enclosure. The drives are configures Raid 5 for about 1.2Tb of space. I am running out of space and don't want to spend a lot for new raid controllers etc. I found another SX4100 online for a great price and it says "duel controller support in one system". My documentation in very unclear about this feature (poorly written). My documentation also says it only supports up to 400Gb drives, my documentation is a few years old. I notice the updated HDD compatibility list from Promise.com http://www.promise.com/upload/Support/Compatibility/1_SS1600_SS4600+SX4100%20SATAHDD%20Compatiility%20List%20V1.0.pdf
lists a few 500GB drives and even one 750Gb drive.
So my simple question is how far can I upgrade once I receive the second controller and how? Ideally I'd like to know if I can really pair two cards to make one array and if so how then whats the largest drives I can use in it.