I'm having the same issue. Game seems to play fine for a bit, but then I start hearing the sound crackling and popping, and frame rates drop. Checked performance monitor in task manager and all 4 CPU cores pegged out at over 90%. CPU and GPU temps at 63 C. Using Mantle API at ultra settings 2560 x 1440 resolution. Low settings and/or DX11 makes no difference to the problem. Runing latest Catalyst drivers and game is patched. Not having issues with any other graphically intensive games such as Tomb Raider or Thief on ultra.
Windows 7 Pro SP1 64-bit
Intel i5 4690k
16 GB DDR3 @ 2400
Sapphire Radeon R9 290 Tri-X OC
500 GB Crucial M550 SSD
If you are hearing cracking and popping, makes me wonder if your issue is with the sound side of the game and not the graphics. It is all linked together so if one has issues other will too.
I have a Phenom II quad core, right now I have hd6950 running about 30-40 fps on med and two high settings, had a R9 290 but it died(manufacturor defect, only 3 days old, lol) and it was running 30-60 on all ultra settings. So on two different cards of Vastly different abilities, I was able to get real good fps, without any major lags or skipping. Wish I knew what was different, but I have no clue.
