vsync always lowers fps so I'd like to turn it off, anybody knows how to do it?

You should be able to go into your video card drivers and select "force off" or something similar. I'll look at the game late tonight and see if there is an in game option.

BTW I hate having V-sync off personally and always force it on except when benchmarking. Reason being that V-sync does NOT lower your frame rate if it is already under 60FPS. In other words it has no effect on your minimum frame rate. What v-sync does is time the output to your monitor's refresh rate. That way only whole frames are displayed.

With V-sync off your video card will start drawing the next frame somewere in the middle of the display so half of the picture is on one frame and the other half is on the next frame. This causes visable lines/offsets called "page tearing". I hate page tearing so I always use V-sync.

Read all about it:

http://en.wikipedia.org/wiki/Page_tearing

Page tearing example:

thanks for advice
I know what vsync is. In theory it doesn't have impact on your min and average fps but in practice I often see that it is quite different. For example Bioshock: when I turn on vsync it runs a lot slower. I didn't check fps but the difference is clearly visible like in most games. Sometimes it can lower your fps to 50% even if game run always below refresh rate. "page tearing" for me isn't such a problem because in most situations I don't notice it. I choose higher fps over page tearing. My pc is 8800gts, q6600.

It would be ineresting to see some benchmarks with Stranglehold comparing 2 and 4 core processors because i saw in taskmanager that this game uses 60-70% of my q6600. It's only one game that I saw was using above 50% of my cpu.