Low FPS in VC

Good evening,

I'm having some performance issues while running the 737NGX in VC. I'll give you the most details as I can so you can really understand the problem. My system specs first (it's a brand new PC):

-Mobo: Asus P8Z77-V

-CPU: I7-2600K @3.4 Ghz

-GPU: Gainward GTX570

-RAM: Gskill 8GB (4+4 Dual channel)

-System SSD: Corsair Force GT 60GB

-HDD where FSX is stored: WD 1TB

-Power Supply: Corsair 850W

The only addon I've been running with the 737NGX is REX 2.0. I've played the first PMDG tutorial with low traffic and clear skies and during the flight I've experienced very low FPS in VC, in a range from 13 to 22, with occasional peaks of 30 (I have set 30 FPS limit whit nVidia Inspector). When in external view, I always get 30 FPS. Before using nVidia Inspector i used to make my tests in LIPZ and I could see that FPS in VC were the same, while in external view were about 45-50 FPS (not having the FPS limiter).

I've already modified my FSX.cfg with the Venetubo tool, but I couldn't get appreciable results. Here is how I set it, I think I did it right:

I have also followed all the instructions for best performance written within the NGX Introduction manual.

Now, the main question is: is it normal to get that low performance with that settings with such a high-end system? I ask you because I want to know if overclocking is the only way out.

Cheers,

Gianluca De Angelis