Framerate runs smoothly but there's an obvious drop

[Syuusuke]

Framerate runs smoothly but there's an obvious drop every few seconds that lasts for half a second. This has been happening when playing TF2 and ME2. One thing though is that I've been playing in windowed mode for both, so we'll see what happens if I go full screen. Though I want to hear other reasons why this happens and solutions.

Nope: Still happens in fullscreen

[Phopojijo]

Upgrade your videocard drivers... that's often the cause of that problem.

If they're the latest... roll back to an earlier one.