Aero 3D Flip Lag

Hi All,

I am new here and this is my first post, so please take this into account... :)

My problem is that when I use my external monitor, then sometimes Windows 7 becomes very choppy, but other times it is smooth (independently on how many programs are running). I saw the threads about the Aero lag during opening/closing windows, but I don't have this issue, I only noticed choppy animations during 3D Flip (WinKey+Tab). If I don't use the external monitor, then 3D Flip is (relatively) smooth. I am wondering whether my system is not powerful enough for a multi-monitor setup (that is why I posted my WEI scores below) or something is wrong with my configuration. Naturally, I have the latest Windows updates, BIOS, Catalyst driver, etc. and I made the usual performance boosting tricks, e.g., optimized the registry, enabled the write cache, disabled some services (cf. Black Viper's site) as well as disabled transparent glass on windows.

So do you think that the 3D Flip Aero lag is normal for my system or there may be something wrong with my setup. Thanks for your help in advance.

Cheers,
Balázs

An update that might help to identify the problem. I have turned my external monitor (by 90 degree) to portrait mode and now the aero 3d flip lag almost disappeared, everything is much smoother. I am surprised, since the number of pixels to be drawn remained the same. Does anybody have a clue what's going on?