Hi newcomer and welcome to the Tom's hardware forum.
U have a very solid mobo that support the X6 1090T BE with a BIOS update, so, u don't need upgrade ur mobo to a $180 mobo if with ur current mobo u can have a very similar performance that with the new 890FXA-UD5.
Save ur money or buy another different thing like a SSD or another GPU for Crossfire, those a upgrades that can add more performance to ur rig.