I cannot try this right now since im somewhere else, but 1440x900 is the native resolution of the screen and it should match the physical proportions of the monitor.Also it doesnt look like it overlaps

When it comes to sizing FS to exactly fit the monitor, I find strange things can happen. Try dragging the edge a wee bit and watch the FPS display.When I notice FPS not quite as usual, sizing is the first thing I check. Appearance of the image, by itself, can be misleading.Alex reid

Strange to read through this thread, as I'm having absolutely none of the performance issues being discussed here. I have always run FSX in a maximized window, and hiding the taskbar makes no difference at all to FPS. I've tried adjusting the size of the window in various ways, leaving a few pixels of desktop on each side, keeping it away from the taskbar, moving the cursor away from the FSX window - with zero difference in FPS.I'm currently using two monitors (normally with FSX in a maximized window on one monitor and charts, vroute, Topcat, and whatever else I need on the other monitor), but my experience with windowed FSX was the same before I got the second monitor.So I don't think it is simply an FSX bug, there must be something else going on, or I would be seeing what you are seeing.

I've been told when FSX is maximized by ALT-ENTER it gets exclusive control of the graphics drivers. When it's not maximized like that the desktop is in control of the drivers without full DirectX and you will have a drop in fps.

Not sure if this is pertinent but during my BaseLining tests I discovered that on average, 15 FPS were lost when the mouse cursor was active over the test window. I use a Logitech trackball so I can't discount that the Logitech driver is the culprit.Other than that i always use fullscreen mode.My OS is Win7 64bit.jja