Performance of FSX is greatly affected by the amount of time CPU spending between foreground operation and background data scenery loading. The lower the framerate is set, the more CPU time is devoted to loading scenery and texture.
FIBER_FRAME_TIME_FRACTION is a direct command that helps tune the amount of time per frame that CPU runs fiber jobs. The function is not present in fsx.CFG by default. To use the function, one can add the following lines in fsx.CFG under the [Main] section:
The default value of it is 0.33, meaning that the CPU will spend 1 millisecond to scenery loading in every 3 milliseconds of rendering.
Any value between 0.01 and 0.99 is acceptable. The lower the value, the better the framerate but also the more the blurry.
What is the best value that balances between performance and image quality for one’s system?
Some people reported that using a higher value renders better photo quality scenery. Others said that this command has no real impact on FSX SP1 or later.
Still testing the usefulness of this command. Obviously, this is another tweak whose effectiveness can only be confirmed by extensive experiments.