Framerates were cut by more than half for no reason?

Question

I have been running X-Plane 11.25 for several weeks at 25-30 fps and now are running from 10-12.  I am running a Win10Pro with i7 and 16GB RAM with a Radeon RX360 4GB.  The only thing that is different is I loaded the Reality Expansion Pack for the stock C172, but I think it was running OK after that, but am not sure.  Last night when I turned on X-plane the frame rates had dropped.  I also run FSX:SE on the same machine and its FPS are the same as before.  

GPU utilization is running about 30-50% mostly, and memory usage is about 2GB.

I have tried to lower graphic settings but does not seem to increase frame rates.  f-act = 11.5 and f-sim = 19.9.  Any ideas what is going on?  I am tempted to reload the program?  Thank you

Answer 1

I would recommend removing the REP add on first. The most likely culprit is whatever changed most recently, right before you started seeing the issue. If it modified the default sim, you can run the installer & pick the update option to restore default files.

Answer 2

If nVidia card there’s two main settings that in default configuration will slow down XP.  Launch nVidia control panel (Windows, right click on desktop, you'll see the option).  Select Manage 3D settings, choose either Global Settings or per Program Settings and choose xPlane. Set Power Management Mode to PREFER MAX PERFORMANCE and set Threaded Optimization to OFF. That’ll help a bunch. 

And, get nVidia driver 398.11 [as of early July 2018, a better one may come along so this isn't gospel], it seems to work really well with XP – faster, less artifacts and overall better quality.

Comments

Thanks for the suggestions and helpful info.  It turns out the problem was with Win10 Pro Power management setting.  It was set to High Performance and got changed (oops...by mistake) to balanced to power saver (not sure), which throttled the CPU speed, which put a hurt on the frame rates.  Also, my Radeon RX560 4GB GPU seems to be doing fine running X-plane.  I am now back in business with good framerates and decent settings for the computer.  Again, I appreciate the help.