So I think it shouldn't be having problems with previsualization, but it does, and very bad.
I can't even select "Good" Preview, because it starts lagging like crazy.
The video has 29.97 fps, but the framerate drops to 10 fps.
And my computer it's fine, new, maybe 3 weeks, and I renewed the thermal paste.
So what's the problem?
P.S. Sorry if the grammar is bad, english is not my first language.
What type of video are you using? AVCHD? AVI? How was this video acquired (ie: camera type)? Just so you know right off the bat, even though the AMD processor you have is an excellent CPU, AMD chips have never been that good for video editing systems.