[quote='Rufio',index.php?page=Thread&postID=65022#p ost65022]Hm i don't think my graca is the problem, it's not the best but it's quite recent and does the job (don't know the specs, i'm at work now so can't lookup). I also have latest drivers.
When I play 2 instances of wow [i]on the same screen[/i] i get a nice 50 fps on both. When i drag one wow window to the other screen, my fps drops on both windows to 10 fps or even lower (feels like 1 fps sometimes).
Meanwhile i have read this is a windows XP (or DX9) problem and not a graca problem.
So I'm looking for a solution that doesn't require me to buy a new component or OS.[/quote]"Quite recent" doesn't say anything :P It can be a low-end or low-mid-end card, which is probably not enough for 2 screens and multiple 3D applications.
You can try to run wow in OpenGL mode and see if this fixes it. (this might confirm that it's a DX problem):
[url]http://forums.nvidia.com/lofiversion/index.php?t15607.html[/url]

[edit] Check this btw:
[url='http://www.dual-boxing.com/forums/index.php?page=Thread&threadID=2175']Horizontal Span vs Dual View on nvidia[/url]
Running in opengl mode seems to fix it. I'll try this at home too, to see if it gives a performance increase.

[edit2, another solution]

step-1
run WOW-1 on current primary display
step-2
switch current primary display to 2nd display ( while first wow session is running )
run WOW-2
done.
both wows will be using full speed of the videocard.