When sweetfx is enabled my graphics are perfect. The problem I got a home built simulator and I have 2 monitors in the dash board. I play in full screen mode and slide the gps etc onto the other dash board monitors . When I switch to full screen mode it's unplayable. Fps goes to almost none. It's def a sweetfx issue because if I disable it I lose my graphics that enhances but play in fullscreen all day long 40-50 fps. Why can't I run fullscreen with sweetfx enabled. Thanks you in advanced for any ideas on how to fix this.

I run SweetFX v1.5 across a 3 monitor setup with the 3 monitors set in Extended mode (so they become 1 monitor with 5760 x 1080 resolution) and get no ill effects.   No doubt, there is a configuration problem somewhere but my brain can't think of where it should be.    It shouldn't be caused by your preset, I don't think...  unless you have some harsh values set in it that your PC can't handle in full screen.

I was playing around with it last night and found if I use monitor and put it in full screen mode it works like a charm. The second I activate the other 2 monitors it won't work. It's a multiple monitor tweak somewhere with sweetfx. Thanks for the reply. Let me know if this pops any ideas.

So you are wanting to play FSX on one monitor and use the other 2 for 3rd party add-ons and charts/graphs viewing?     I can't do that.  FSX flips out if I put my monitors into individual mode.   The frame goes to crap.    Put it in extended mode and go full screen and it runs great.   I'll think on it.

Exactly. Now with out sweetfx I can do exactly that and still get 40-50 fps. But soon as I enable sweet fx it won't allow it. When I enable sweetfx it puts in it files dxd9.dll etc and apparently that is preventing full screen mode on multiple monitors. I'm wondering if I should build a second computer and run the misc monitors off of that.

If they are all 3 the same size monitors I highly recommend just put them in extended mode, run full screen across all 3 and use a laptop for your 3rd party stuff.  It's how I operate.    I use Aivlasoft's EFB on my cheap little $330 ASUS laptop and network it to the flight sim PC for all my charts and flight planning needs.  Works well with VatSIM online flying too.   I do all my fuel planning, pulling up additional charts and as much stuff as I can on the lap top and leave the flight sim PC to do just one thing; fly.   I don't know to fix your problem though.   I tried to run it your way once and with SweetFX on and the entire thing became a slideshow.