I don't have dual slot gpu, but I already have a long format gpu which cover the sata port which stays there lonely a bit. There I used a sata cable with 90 degree male connector and fits nicely below the card. You can insert one more connector which sits below the second card, but I believe you still will have one sata connector, in the middle of those three, where it would not fit easily a 90 degree connector, being too close to the other one. But I am wrong, and just nicely you can lay down the cable on top of the other. Surely the space between the gpu and the connector would allow that, but the connector once is 90 degree, it may reach the next connector. Probably one sata port may remain blocked, depends on the video card's width. I have never seen sata cabled which are 90 degree but flat, going to right side as you see the image. If you have a cable like that, you solved everything.