As you have installed a new hardware it is always good to have a look at the Bios, and see if something changed there.
If all is OK in the bios, and since you´re using the latest driver update, and the problem wasn´t there before, then the only thing that comes to mind is that you may have got a faulty GPU.
If so, then you should contact your card manufacturer for a RMA.
well.. RMA is the last option that i can do..
but i still hoping this problem can be solved by myself. maybe theres anothers factors why this problem happen to my pc..
anyway thanks for the answer