AMD Crossfire having issues, please help!

[Killervolt]

Hi, I just paired a Sapphire R9-270X with an MSI R9-270 in crossfire, and I'm having some issues with them. 

Firstly, the clock speeds are not matching up. I understand that in CFX the higher clocked card will match the speed of the slower card, but in both MSI Afterburner and AMD Radeon Settings, they are clocked at 550 and 475 MHz respectively- not sure why. I have tried increasing the power limit and bumping up the speed, but it keeps on resetting. Could this be because I only have a 500W power supply and the cards are underclocking automatically? Secondly, I am getting lots of screen issues- Occasionally for no reason my screen will start to flicker like an old analog TV and can only be fixed by restarting. Also getting stuttering and freezing. I have tried re-installing AMD drivers but nothing seems to work. Any help will be appreciated. Thanks!

[DaBeggad]

AMD having probs... didnt expect that  sounds more like your cards are clocked too high could be the psu or driver probs