Guys, check this report and try to reproduce it. Please vote and contribute if you do. This is the actual cause for my stutter when panning on the ground, its a weird one. 
 

https://forums.flightsimulator.com/t/strange-stutter-when-the-sun-is-at-180-of-the-camera-u-get-a-stutter/536835

Yes... that behavior was identified in this very forum about a year ago (and it still appears to be the case in SU10): 

Here's a recap of my findings:

• When panning/turning a 360 degree circle, there is a pronounced long frame (maybe a quarter second or so) at one particular point.  All other things being equal, the stutter always occurs at the same point which is always opposite of the position of the sun... but about 20-30 degrees offset from the direct reciprocal (i.e. not directly opposite).  I also occasionally notice a shorter stutter on the other side of the reciprocal.  This can be confirmed by changing the time of day/sun position and noting that the stutter point has moved.  I suspect that it may have something to do with rendering shadows or reflections (which probably aren't cached); but that's just a theory.
• The issue only occurs on the ground.  Once above about 50' AGL, the problem goes away.
• Changing the pre-cache to LOW pretty much resolves the problem for me.  I no longer experience the stuttering and my system is apparently fast enough to avoid most of the culling/pop-ins/re-draws that I've seen others complain about.

lowering pre cache didn't work for me, if fact the opposite., I set it back to high, but still panning problems, also I noticed increased degradation I couldn't do a second leg without restarting my pc possible memory leak?, no expert lol

3 hours ago, roi1862 said:

Guys, check this report and try to reproduce it. Please vote and contribute if you do. This is the actual cause for my stutter when panning on the ground, its a weird one. 
 

https://forums.flightsimulator.com/t/strange-stutter-when-the-sun-is-at-180-of-the-camera-u-get-a-stutter/536835

I tried to reproduce it but I don't have this problem. I can pan the view all around the aircraft without stutters. I'm using a G-Sync monitor though, before having it I had some stutters when panning.

1 hour ago, Alvega said:

I tried to reproduce it but I don't have this problem. I can pan the view all around the aircraft without stutters. I'm using a G-Sync monitor though, before having it I had some stutters when panning.

Same, haven't noticed this. And I would think having the pre-cache as high as possible is generally a good thing with regards to stutter-free panning. 

11 minutes ago, Cpt_Piett said:

Same, haven't noticed this. And I would think having the pre-cache as high as possible is generally a good thing with regards to stutter-free panning. 

I agree, mine is on Ultra.