Texture loading

So i recently bought a new video card - SAPPHIRE NITRO Radeon™ R9 380X 4G D5. So the problem is that my textures are loading slow causing suttering/lags. Someone know how to fix this or what could be the problem?

Try to give it high priority in the task manager

Tried that already

Did you try setting affinity to all cores?

It was allways set to all cores