GPU bottleneck?

[bloodhunter]

I like using MS FSX a lot and have quite a few add ons that require a decent GPU. For some reason I am not getting a good FPS with some of the add ons running and members of the flight sim community say my GPU is bottlenecking my CPU and a GTX 660 would pair up with the CPU much better.
(system spec can be seen in the sig strip.)

I just don't fancy spending on a GTX660 if it will hardly make a difference.

Your thoughts please.

 

[bloodhunter]

What GPU do you currently have as your signature is saying that you already have a 660?

OOps, I meant to have said I don't fancy spending on a 680.

 

[bloodhunter]

Thanks everyone. It seems to be working well again for some reason as I have made no changes either.
Using the default Cessna 172 and the frame rate set at unlimited I am getting around 130FPS and about 80FPS when using say the detailed 3D cockpit in PMDG 737NGX.