When ever I have the client running I get lag spikes. I noticed the issue in cs:go, but I then tested it in Insurgency and CoD4 aswell. Both other games you can see the same drop in the fps meter, but I'm not as sensitive to lag in those games.

Here is a video showing the net_graph in CS:GO (I usually have around 400 fps, but I set fps_max to 150):

As you can see the fps, var and sv are all fluctuating in what seems like rytmic pulses. It's hard to show the actual lag on a video, but it's very annoying to me. This is recorded on a local CS game with TS3 only running in background without being connected to a server.

This problem have persisted over a reinstall of windows. Same problem when installed on either hdd or ssd, 64-bit or 32-bit. I currently have an overclocked i5 2500k, all though I'm 90% certain I've had this problem since before I overclocked it. I will try resetting it when I come home, allthough I don't think it will help.

Hard ware:
CPU: i5 2500k @ 4.5 GHz
Sound Card: Asus xonar DG
GPU: Nvidia GTX 680
Mother board: AsRock extreme 3 gen 3
Storage(OS): SSD

All help appreciated!