Hello, I just built a new computer and placed my GTX 780 Lightning in the second PCIE x16 slot on my motherboard, however I only realized later that the motherboard manual says that that slot is only used for dual graphics cards at x8. Will the my card still run at x16 despite this since their is no other graphics card? (My wiring is very delicate and I would like to not to have to remove the card). Essentially will my card run at x16 or x8?