RX480 Asus Strix Black Screen, Performance Problems

Okay. So here is my problem, i got a crossfire of two RX480 ASUS STRIX and when ever i try to update the driver while CrossFired  my screen goes black and forth for few times and in the fifth to sixth time my computer freeze for about 15 minutes, and when i try to move my mouse it's not responding for a while and then its blink to a different spot on the screen.

i found the problem was with the crossfire after trying to use them Separately. they worked fine on their own but on crossfire the screen goes black while installing a driver or while playing games the performance is dramatically going down.

Each GPU gets his own 8 pin connector.

My build is:

motherboard : Msi carbon gaming pro x370

cpu : ryzen 1700x (3.4GHz)

ram: 2x kingston ddr4 8g 2133mhz

power supply: antec 1000w

SSD: hyperx 240gb

HDD 1tb

case: corsair 750d airflow

 

 

and here is my dxdiag if it will help.

though right now I'am running on my computer only one GPU