I went ahead last night and pulled up some Crysis 3 at 1080p with 2 R9 290X. It played well most of the time maxed out but it still had sections that ran low so that could be the issue there. Crytek has been having trouble lately and honestly this game never really hit good levels of optimizations for the power it needs.
As for BF4, in multiplayer I did notice some drops into the 50's with two cards on Siege of Shanghai and on the water map (Name leaves my mind, the one with the storm and ship crashing). It never really always utilizes the cards sometime properly at 1080p but with Mantle and DX 11 changing back and fourth at 1080p I noticed that I droppped below 60 rarely with Mantle on vs DX 11 so you could try that. My processor was being punched alot the whole time and I am running an FX 9590 a bit overclocked so who knows.
I switched back to 4k and all three and things seemed to be used a bit more overall on both games (Crysis though was around 30-60 depending at times with 4x MSAA and Ultra settings) on BF4 the game ran about the same but with it running Ultra with Mantle around 50-70 FPS depending (Vsync off) and with it on (I use aftermarket dynamic Vsync on Radeon Pro) It kept a 60 with a few rotations around the 55 are and back to the 60.
I will say this, you maybe just hitting some limits sadly with the overall system and games. My suggestion would be to buy a AIO LC unit or something and try overclocking the CPU a bit because even if the utilization is not to max on the CPU, you still see improvements across the board.
Thank's for you input. I had the card in Uber mode. And i'm most certain that they didn't throttle. Because the Core and Mem clock was always at the maximum MHz when gaming. Today i returned the cards, cause i belive that there is a general problem with certain R9 290 in Crossfire that AMD must fix.
So thank you everybody for you help, it's must appreciated. I will definitly stay on this forum even though i have returned the cards.
I will most likely buy a non stock GTX 880 when it arrives.
Thank's again guys.
Oh well ok whatever makes you happy sorry we were not able to fix your problem. Hopefully whatever you buy next will give you less trouble.