I have had this issue for a year. At first i fixed it by reseating video card. But it ran at x8 eventually. I reinstalled my os window 7 sp1 but no luck. Here are what i tried and failed: get rid of dust of video card slot by using air compressor, clean video card (litterally), reseat both cpu and vga, install latest driver including beta driver, clear cmos. I even changed a different card (fully working) it still ran at x8. So i guess my mobo (asus p55 chipset, no usb 3.0 no sata3) is malfunctioning. I installed vga in the first vga slot (16x slot according to manual). So what should i do to make it work again? I am experiencing quite a frame loss in gaming. Update1: Yesterday i inserted my hd5830 in a spare machine (i3 540, mobo with h55 chipset) and guess what it ran at x16 bandwith without a problem. So can i conclude that my mobo has failed? P/s: Any advices, suggestion is appreciated.