VSync tries to keep the framerate of the game locked at the same value as your screen refresh rate.
In other words, if your hardware can calculate 100 pictures per second, it will try to send those to your monitor.
A monitor has a fixed refresh rate, though (typically 60Hz for most LCDs), so only 60 pictures can be displayed per second. If your GPU produces more than that, this can result in screen-tearing, so you can enable vsync to lock your framerate to the refresh rate of the monitor, giving a smoother experience. If your actual framerate is lower than the monitor's refresh rate, either nothing happens or it will be reduced to e.g. half the monitors refresh rate (30 fps in that case).
An additional effect of vsync is that it can reduce strain on your system, since it might have to do less calculations (if you would have higher fps without).
What you can do against overheating depends on the cause of the overheating.
Just putting in some more fans will probably do nothing.
You can see if the fans/coolers are dirty (dust likes to settle down in the fins of the coolers) or not working properly anymore.
Sometimes it might be necessary to re-apply the thermal grease, but I would recommend this only if you have some experience with assembling computers.
There are tutorials to look up on youtube though.
Last edited by El Zoido; 19/08/13 03:52 PM.
