Games running at 60+ but looks laggy?

[Dragoon_]

Hello knowledgeable members of Tom's hardware forums,

I've built a new system designed for gaming specs are:
I5 3570k [OC to 4.5ghz]
8 Gigs HyperX Black RAM
1tb Western Digital Blue
258 Gig Samsung 840 pro SSD (boot and games: BF4, DotA 2, Shadow Of Morder)
450W PSU
Hyper 212 Evo CPU Cooler
Windows 8.1 64 bit

(And yes I have tested on Prime 95 for a day on my proccessor to check a stable and non-throttling overclock)

Anyway, my problem is when I'm playing games at 60fps plus, with my monitor running at 60hz my games look like they are running at 30-40 fps. However if I overclock the monitor to 70hz the games look smooth as butter ! I have tried re-installing Windows, re-installing RAM, completely wiping the system and I just want to know what causes this horrible lag and if there's a fix for it. I will be glad to provide any more information if needed.

Thank you for your time.

 

[Lmah]

Is v-sync on? You get more input lag at lower frequencies. Try with v-sync off.

 

[Dragoon_]

Is v-sync on? You get more input lag at lower frequencies. Try with v-sync off.

I always play with v-sync off, have tried with it on, makes a little difference but not a lot

 

[berny2220]

What GPU do you have? Also try disabling shadows.