R7 260X Clock Issues

I have an Asus R7 260X oc 2Gb graphics card in my system and when I run it at the stock clock it comes with I get glitching in my games such as patches of discoloured squares on the screen, but when I under-clock it the card runs without a problem.

Any help would be appreciated. 

Id dare say your psu meets the power requirements as 260x's only state a requirement of 19amps.

If you can test the card in another system, great.

Although by the sounds of it the card is a dud and you'll have to RMA it.

ok thanks for the advice.