I noticed the largest increase running more AA and AF while using high LOD, like 6.5 in Orbx land... With default scenery/planes you probably won't notice a huge difference between 3.9 and 4.6. Start adding fps hogging payware planes and scenery, traffic, high levels of driver-level video card stuff and you'll notice the extra MHz helping you out.

Isn't AA + AF taken care of by the GPU?

Well, I don't know about your experience but the difference between the 2500k @ 3.4 and 2500k @5 ghz is unbeleviable.

I agree -- but mainly with complex add-ons. I suspect a default FSX even with sliders pretty high does okay on the normal turbo boosted 3.9 GHz speed, but once you add complex aircraft, complex scenery, realistic levels of AI, and layers of hi-res clouds, the 4.8-5 GHz range becomes pretty important. I wouldn't be able to fly into and out of my UK2000 EGLL with the settings I like with anything much less than 4.8 GHz. That was my only reason for upgrading processors and getting it overclocked!Even then, in order to not suffer less than 20 fps whilst landing at EGLL I can't use LODs greater than 5.5. (Clouds come in useful to hide the latter's shortcomings, though <G>).RegardsPete

Thanks Pete! It will surely be interesting to see how adding addons will affect my benchmark flights!