I'm building a new external raid for editing video at the moment. I currently have a 8bay 2x eSATA port based enclosure. It works well although I really want hardware based RAID and from what I can tell once you get in that league the connection evolves into SAS connectors. From what I can see SAS is backwardly compatible with SATA.
My main problem is my budget is running dry and I can't afford to replace both the card and enclosure right now.

My question is - do SAS based ports support port multiplication at all? If I buy a common SAS -> 4x eSATA cable - can I connect it to our enclosure and have all 8 drives show up?
There doesn't seem to be a lot of coverage of this on particular cards specs so I'm throwing it out here to see if anyone has tried or knows.