Having issue with new video card on a old Mobo

Too, I should remind you that until AMD's AM4 Ryzen platform is released soon, all current AMD PCIe support is PCIe 2.0. No PCIe 3.0 until AM4.

I didn't think I had turned on dual graphics. How do I turn it off? Do I go into northbridge in the bios to disable it?

Trying to find out if it is my mobo or if it is a default setting with my new video card. I have a AMD a85x extreme6 with a AMD 64 3800ghz processer with 64gb maxed ram. I replaced a old NVidia 550ti 1GB with a Radeon r9 380 crossfire game video card with 4gb memory. That is a 3.0 support and it works but radeons relive crimson is showing the card as a 2.0 x8. when I play WoW it seems a little sluggish but I would think it would run smoother. Cpu temp at 20c and after running WoW it is at 45c Then mother board temp was sitting at 123F all the fans are working even the one on the CPU. Would think the card would be seen as a x16 not sure if that would play a factor or not.

What I did next to see if it would correct the issue is I ran a DDU to remove both video drivers related to my new card and some remaining from NVidia. I went into the bio's and just put everything back to default settings. Got the new crimson driver 17.2 installed and when I load up WoW it still seems sluggish I even deleted the 3 folders in its folders before running it. That the game itself would only recommend 5 but it still seemed sluggish. Crimson still still only seen a 2.0 x8 but memory and core clock was blank. My next check to see if it does it with metal gear on high settings and GTA.

Side note not sure if it is anything but when I checked amd overdrive it had 2 video cards listed the onboard radeon 7660 HD and then my r9 380. Should that be? Only thing I haven't did yet was mess with the bio's with the video settings. Not sure if that would correct my issue or not if I adjusted it. Makes me wonder if the system thinks I'm using 2 video cards instead of just 1 since it is using a x8 instead of a x16.