I had this same issue playing world of warships. With driver 16.12.2 my fps would constantly bounce from 75 to 25. I went back to version 16.12.1 and now have constant 75 fps. I tried the new 17.1.1 version and it has the same issues. System is as follows:
R9 Fury x2 in crossfire
Gigabyte G1 Gaming 7 motherboard
16gb G.Skill 3200 ddr4 ram
Windows 10 64 bit
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