Its not that it uses the slot, it's more than there is very little space left after the 2 cards.
I could probably squeeze the card in between but will that have any negative heat effects? Either on the card because its sandwiched between the 460s, or the 460s themselves?
Also would the card offer the same speed as if I had a newer motherboard?
The benchmarks I am getting off this Vertex 4 are horrible at the moment and not anywhere near what they should be.