I have a very similar system to yours - i7 2600k OC 4.5GHz, GTX580 1.5gb. I'm also running FSX and Windows 7 64 bit off an SSD. I don't think your problem is with FSX / graphics or cfg settings.....The only time I get stutters are for 3 x reasons -1. If I set the FSX frame rates to unlimited - I get big jumps in my fps sometimes 25fps to 150+ fps. It's definitely these massive variations in fps that cause some of the stutters. The only way to fix this is to limit my framerate within FSX to around 30-40fps (depends on which add-ons i'm running) Obviously when you use FSX's internal framerate limiter - you loose some performance (FSX eats around 5fps when you limit) This is why it's best to use an external framerate limiter. N-vidia Inspector now has this function built in and I've heard it works well (i'm still waiting to try it - Wife permitting!)2. The other thing I have to do is switch my anti-virus program to 'Silent Mode' - This sometimes causes some latency issues within FSX when it suddenly decides to do it's own thing.........3. Last of all - I disconnect from the internet. My system always seems to be trying to do something when i'm connected and this also causes my micro stutters.One last question - Are you using Track IR?? When I have my micro stutters - I notice the LED Light on the left side if the IR receiver flickers on and off when the stutters are happening. Disconnecting from the Internet cures this every time.Hope that helps a bit?Dan Pye