dual graphic card

hi there is h61M-d2p b3 and h61M-usb3 b3 support dual graphic card if not what does this mean:
1 x PCI Express x16 slot, running at x16 (PCIEX16)

1 x PCI Express x1 slot

and also i want to know about h61M-d2p b3 and h61M-usb3 b3 motherboards difference.

and also the difference between h61M-d2p b3 and h61M-usb3 b3 gigabyte mother board with Asus p8h61 mle and Asus p861 mlx which one is better.
having usb3 is not important for me and of course one PCI card is enough for me but if the gigabyte model support dual graphic card i want it!!!
thanks

Intel has a range of Chipsets.
The most recent one is called the Z77, I would not recommend buying an older chipset as it may not be future compatible.
The difference between the two motherboards that you stated is that the second one had USB 3.0. and an x1 slot, making it a bit more compatible.
If I was you, I would buy the Gigabyte Z77-D3H motherboard so that you can guarantee that your computer is compatible with all of the modern components and is relatively future-proof.