cpu usage over 90% i5 4670k

your ram and hard drive are lacking

would a clean up and reinstalling Windows and everything could help?

Dont listen to him he is full of **bleep**. Your ram and SSD is fine. If your OS install is pretty old a fresh install can always help some, but if you know how your better off cleaning it up yourself with some tools. If you dont, just backup what you need and do a fresh install. If your on Windows  7, unpark your CPU cores (google is your friend).

i have unparked my cpu but it didnt help. i thinking about updating the bios right now before reinstalling Windows.

since it's not HT enabled it is nomal, because BF4 uses CPU powers alot. In win 8.1 bf4 uses ~80% of i7 4770k@4.2GHz

if i disable HT on my i7 4770k it is 100% loaded as well, and i do have some fps drops due to CPU/memory combined with software. But when it occurs my CPU isnt 100% loaded and my 2SLI 780 GTX Lightnings are not 100% loaded either.

Partially Win8.1 solved the issue (70fps min -> 100fps min) but the bottleneck still exists somewhere in software or OS.

you need to check out if it is your GPU that bottlenecks you or software. In order to do so just check you GPU usage while expiriencing lowest FPSes if its not 100% then upgrading win7 to 8.1 would help. More info and benchmark you will find here http://www.overclock.net/t/1433904/comparison-of-windows-7-vs-windows-8-8-1-ht-enabled-vs-disabled-on-battlefield-4/130#post_21303405

as for solving this, try going MESH DISTANCE = high, MSAAx2, FXAA=medium, Occlusion=SBAO, render quality 90%. This might make it playable with minimum losses to image quality.

im getting over 90% usage for cpu and gpu, sometime its at 100%. i have updated bios but didnt change anything. i cant figure how i can disable/enable HT in bios, i dont see where it is. looks like w8 gives more fps but i wont change that just for a game, this is ridiculous. i cant believe i have those fps drops even with that rig. i guess the game is just not optimised. ill wait for the next patch witch is coming in 2 day and see if it change anything. if not, then ill do a clean up and reinstall w7.

you don't have HT on your processor.

It seems to be both game wich is not optimised for now (it is clear when u see frame time variance disturbance and compare it to optimised game like quake live) and microsoft software which doesn't deliver the result it should, even in their own directx api.

here is quake live frame time varience (notice how smooth it is)

http://www.overclock.net/image/id/7350156/width/900/height/900/flags/LL

and here is bf4 on my pc

http://cdn.overclock.net/1/13/900x900px-LL-132584b1_win81fps_gameplay.png

Try to find if there is some software starting at boot time that is causing an issue. Do a clean boot and see what happens: http://support.microsoft.com/kb/929135

that doesn't help. 

It seems that more or less everyone has those high CPU usage issue, those who got top tier cpu don't mind too much, cus it doesn't affect them too much, but those with weaker cannot achieve decent fpses even with 700$ GPU and 300$ CPU which is kinda weird.

i think the game isnt optimised, dice have released an incomplete game. i think my pc is more than enough to run bf4 in ultra without frame drop.