I'm currently using a Sapphire Radeon R9 380x 4GB GPU. I was wondering if I got an ASUS Radeon R9 390x I could run the 2 cards in crossfire. My mobo is the SUS AMD 970 PRO GAMING AURA LED Motherboard. If not, are there any Nvidia GPU's around the £300 mark that have an equal or better performance of either 2 cards? Cheers