I give up. Have the newest driver directly fron NVIDIA and I don't feel like try and error installing all drivers they ever had (already installed like 7 this weekend).This is my situation:With unlimited frames I get high framerates but stutters every second that make it unplayable (They will go --- 60..55..60...48.. 5 (!) ..50..60..65..30.. 5 (!) ...).Frames limited to 25 - everything is fine, but of course, due to the known bug in FSX when in a large hub, frames will be about 33% decreased from what you would get when running unlimited. The new limiter ("Governor") solves that bug, but some of the stutters from unlimited mode will remain.I begin to wonder if this is totally normal that in some situations (ultralight on runway of large hub), running unlimited is unplayable.

I give up. Have the newest driver directly fron NVIDIA and I don't feel like try and error installing all drivers they ever had (already installed like 7 this weekend).This is my situation:With unlimited frames I get high framerates but stutters every second that make it unplayable (They will go --- 60..55..60...48.. 5 (!) ..50..60..65..30.. 5 (!) ...).Frames limited to 25 - everything is fine, but of course, due to the known bug in FSX when in a large hub, frames will be about 33% decreased from what you would get when running unlimited. The new limiter ("Governor") solves that bug, but some of the stutters from unlimited mode will remain.I begin to wonder if this is totally normal that in some situations (ultralight on runway of large hub), running unlimited is unplayable.

try regenerating your fsx.cfgbut backup fsx.cfg and standard.xml first

try changing the texture max load line in the fsx.cfg file to 4096 from 1024. also get rid of any bufferpools tweaks

Try going to this airport 0CL0 [Yosemite], take off and fly around, fly eastbound and report back - do you have microstutters in this "area"?

After spending the entire weekend on this issue without a solid cure, I guess a reinstall is the only solution (again). But not now, I'll let it sit there for a while, really got angry with it by now.Thanks everyone for your input!

If you are gona reinstall, some suggestions cause i have done about 5 reinstalls recently.I have a 1 tera drive where i can put backup of fsx main folder and the relvant settings in windows. I just copy the whole user settings folder in windows.Make this backup as soon as all is installed and you happy with perfomance . Also i have removed rex2 and gone back rex1. And some stutter related issues are gone. Maybe i need to choose small quality textures with rex2.Defrag

One thing that doesn't seem to have been mentioned by anyone is Ken Salter's Alacrity utilty to shut down all the rubbish you don't need when running FS. http://alacritypc.kensalter.com/I'm not sure that will cure microstutters but it can't do any harm.Also, when I start FSX (under FS Limiter), I set its Priority to High and Affinity to all cores EXCEPT 0 using Task Manager. Most of the low level utilities which have to be left running seem to use Core 0 by default, so doing that I suppose avoids some conflicts with FSX.