With the pics, i admit my other statement is completly WRONG.  The ' other ' multipliers I could find ( some on eBay, the actual ICs on TI.com ) were mostly 2x with an option of what speed and thus a colour difference in slots IF it had 4 slots.  Just looking at the pic of the actual card, there are more pins on that one multiplyer IC ( over 40ish in quad flat pack ) and it definitly looks like it actually talks to each slot individually.  I'd love to find out the hard coded limit ( if any ) for GPUs with that kind of thing.