A bottleneck is a system specific event. It rarely occurs between components, especially if the components are all modern. No, your memory is not going to be a bottleneck. Get that CPU, use those other components listed in post #1 and see what your computer is like.

Have got and installed that CPU now. My first impression is that FSX is smoother but fps hasn't changed much. Big cities and ground object shadows is bogging down my system. But the stuttering is less pronounced now. In the PNG bush addon for pacific ocean the smothness was even more evident and also the fps was stable at around 30. I use a external fps limiter set to 30. In FS9 at kewr with aerosoft Manhattan and F1 C172 with reality XP gauges I could see fps drop to the twenties (no external fps limiter there).The most evident performence improvement during these first short tests was in another 3D game Total war shogun 2 during battles and accelerated time. I expected the most improvement in CPU intensive FSX.Should I change any settings or tweak now thast I got four cores instead of two?

Now, run the tweaks that are generated on J.B's site. Sorry I don't have a link, but someone else will.