New computer getting fps spikes on Counter-Strike 1.6

Hello,

I recently bought a new computer and everything works fine, I play League of Legends, Borderlands, Left 4 Dead all in high settings and I get constant fps and very smooth gameplay.

But when I try to play the oldest game ever (Counter-Strike 1.6) I get fps spikes very very often. I am playing in OpenGL, yes. I disabled vsync, yes. I even went to my nvidia control panel and just straight up set everything up for high performance and not quality and I still get fps drops to around 40's-50's.

My computer specs:
-Intel i5 3.3 Ghz (Turbo Boost 3.7) L3 Cache 6MB, Quad-Core, 32nm
-2x Kingston 4GB DDR3 (1333MHz - PC3-10600)
-Seagate 1.5TB HD 32Mb Cache, 7200RPM
-ECS NVIDIA GeForce Black GTX 560 Over Clock, 1024MB GDDR5
-Windows 7 Professional

I don't know if you guys need anything else?
Got any ideas?

Cheers, thanks.