Thought it was time to upgrade my computer since it was getting old and I really couldn't upgrade it for speed, besides   I was still running windows xp (yes xp). I up graded with:
Levono 6th Generation  i7-6700K 4.0Ghz
NVIDIA GeForce GTX 970 4GB
8.0GB DDR4 UDIMM 2133 MHz
2TB 7200 RPM + 8GB SSHD with operating system on a 120GB SSD.
Windows 10 64 bit.

I install the 757 and when starting at KATL (this happens at all airports) (using freeware KALT scenery) frame rates start out good, around 30 or so, but by the time I taxi frame rate drops into the teens and if any delay for traffic at runway it can drop to 7 - 10 FPS. I never had this problem on my other computer and it was a lot slower than my new computer. Once I take off and in flight the FPS go back up into 30's, Then when I start to descend into destination frames start to drop and by the time I'm on approach my frame get down into single digits. I did some tweaking and now it drops into teens. The flight when looking outside vc is still smooth with 12 or so fps, it's just that then panning with hat switch or TrackIR gets very jerky.
I had read a post from back in 2014 about someone having the same issue (just not with win. 10) and they thought it was a sound issue and when replaced they 757 sound with a CS 707 sound flights were back to normal for them.

So, does anyone have any idea if this could be the problem and if so does anyone know what sound flies would need to be replaced or if their is a sound update for the 757.
If this is not the issue, does anyone have a solution to this problem.

I haven't tried my another company 737 yet, but i did fly my a2a c172 with no problems at all. I wonder if it could be a windows 10 issue. I'm sure windows 10 is the problem, so i hope I can find a solution to this.

Oh, forgot to mention I tried with frames at unlimited and locked at 35 (75mhz refresh rate) and these made no difference.

Thanks for the help,
Gabe