Well, i recently installed a new motherboard and since then i have been geting some frame drops.
It goes from 60 to 30 and then back to 60.
With the motherboard i used before i could play Crysis 2 at medium settings with no framerate drops at all, but now i can't play cause it does it so much.
I have an sapphire ATI readeon 5700
This is very strange the problems i could imagin are:
1- Have you installed all your motherboard drivers correctly? also check video card drivers, reinstall them again, could also be, old video drivers were having more frames on that specific game.
2- Does that motherboard have also a pci-e 2.0 16x? it would be possible to have a little performance drop if your gpu is connected on a x4 slot
Vsync do that. Activating V-SYNC when framerate is under 60 it goes straigh to half, (30fps) ,so it is not a good option activating it if you are having FPS flutuation.
GPU = Graphics Processing Using = Graphics Card = Video Card. have you download latest driver version + catalyst control center? that helps a lot the framerate. maybe you had it installed before and now it is not correctly installed: http://support.amd.com/us/gpudownload/Pages/index.aspx