Very bad performance (cpu+gpu spikes when being shot at)

Thanks for the reply, I did everything you said and I still have the same spikes. I even did a clean install of windows 8.1, and tried all of the things you said, and still no joy.

I am running the following system:

Asus 120 full hd monitor

Intel i72600k oc 4.4ghz with a mugen 2, with 2 fans in push pull, temps are excelent.

Corsair ddr3 1600mhz 8Gb 4x2gb sticks

Crucial M4 SSD

Evga Nvidia gtx 690 no overclock, and temps are also good

I have this installed in a Coolermaster Cosmos 2, with very good airflow.

Os Windows 8.1 clean installation fully updated

Nvidia drivers 335.23 

Audio realtek 889 drivers 6.0.1.7023

Antivirus - windows security essentials

I have tried older Nvidia drivers, and beta drivers, I have disabled all programs running in the background, I have disabled my onboard realtek soundcard, I have disables my cpu overclock, I am running high performance profile in windows energy management. I have enabled high performance, thread optimizationm, vsync of, render 1 frame ahead, single screen performance, in Nvidia controll pannel, Of course I also tried it without all these options.

I am running the game in 1920 by 1080 120hz I also tried 60hz with vsyn enabled and disabled, I tried the lowest possible settings and the highest, with both scalling and vsync on and of, I tried a mix of low medium ultra, the GTX690 has 2gb vram, and when running Ultra it is very close to 100% full, but on lower settings I have enough vram, and I should not have these weird spikes. I also tried this with the x86 version, and I am running them as administrator.

Again when BF4 came out I could play this game with every setting on ultra with 120% scalling on 1920 by 1080, Anti anti aliasing max with a fov of 90 and I could play the game between 60 and 100+ fps, with some fps drops, but I did not have these spikes/freezes when I am being shot at. Something changed 3 patches ago, and now I really don't enjoy this game. I can run across the map with no problems what so ever, running perfectly smooth, but when I am being shot, or a explosion goes of near me, it freezes for just a milisecond, so I cannot react fast enough to shoot back.