Rx 480 4gb crossfire usage problems

[soffver]

im currently testing my pc on battlefield 1 with Dx11 with ultra settings and no AA, 1080p

when im only using one GPU i get a stable usage on the gpu.
(https://gyazo.com/2319bade693ae39294a013f8056435c0 (GPU2 is GPU1, its just displaying wrong name))

but when im using two GPUs in crossfire i get this realy unstable usage
(https://gyazo.com/e8af157cc1c176a475dd512b3e95e60e (same here, GPU2=GPU1 and vice versa)) 

 

The bad usage on crossfire is causing lower fps and fps dropps / unstable performance, in-game graphics flickering and worse overall performance than one card.

does anyone know how i could fix this problem?

 

I have tried both cards sepatately one by one and both have a stable usage.

specs:

gpu: ASUS Radeon RX 480 Dual OC 4GB (two of them)
cpu: Intel Core i7-6700K 4,0Ghz 
ram: HyperX Fury Black DDR4 2x8GB 2400MHz 
mobo: msi Z170A krait gaming 3x
ssd: 240gb corsair
psu: EVGA SuperNOVA 750B1 750W

[soffver]

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