This could be a compatibility problem, you may need to update the BIOS of the motherboard and the firmware of the card and test again. In addition check if all the power cables required are installed depending on the video card installed.
Additionally check with the video card manufacturer if the card complies with the PCI Express* specification supported on the motherboard, those specifications are available on page 19 on the following site
Check with the video card manufacturer for any compatibility issues reported with those cards and the motherboard
you got it. you need pcie 2.0 compatible video-cards for your board.
Thanks everybody for reply,
Finally, i find that if install Power supply with 24 pin -> it work fine.
It's wierd that this issue doesn't occur on video card HD3450 (PCIe 2.0).
Note: remove vga onboard driver before install the external vga card. otherwise, we can't login into windows bc driver conflick.