I'm trying to turn off the framerate limit in PX1 1.0.2.0.  I been trying various permutations of the following:

1. go to Advanced Setting > Framerate Target,
2. uncheck the Framerate Limit (which I've had turned on and set to 60 FPS forever),
3. left-click on the 0 profile (which is what I've been using),
4. hit the Apply button,
5. again left-click the 0 profile and hit the Save button,
6. shut down PX1,
7. restart PX1.

Upon restarting, the Framerate Limit is again turned on and set to 60 FPS.  If I check:
 
C:\Users\Dave\AppData\Local\EVGA_Co.,_Ltd\PrecisionX_x64.exe_Url_vrvasebqwl5wesi2q3tshmshuzsvqfah\1.0.2.0
 
the timestamp of the user.config file has been changed to match the time I saved the configuration. However, looking for the term "framerate" in that user.config file give one result and it is:
 
"            <setting name="FramerateLimit" serializeAs="String">
                <value>60</value>
            </setting>"
 
which implies (to me) that the framrate limit has not been turned off even though the file has somehow changed.
 
If I go through the process again but make some other change (for instance, going to Setup and turning on the Splash Screen option) as well as change the framerate limit, that other option gets changed, but the framerate limit remains unchanged.
 
I'm not going to go through the standard work-around of clean uninstalling this software yet again to make this setting stick.  Can I just edit the user.config file in some way to turn the framerate limit off?  Perhaps set it to 0?

If you're using a NVIDIA card, the newest drivers have a frame limit setting now. Better to do it driver side.

I finally got around to setting the "FramerateLimit" value in
 
C:\Users\Dave\AppData\Local\EVGA_Co.,_Ltd\PrecisionX_x64.exe_Url_vrvasebqwl5wesi2q3tshmshuzsvqfah\1.0.2.0
to 0 (zero) and it seems to have done the job.  Thanks Sajin.

The framerate limit never works for me at all in X1. 
 
It works in nVidia but I get horrible stutters every few minutes (from max 150fps down to 30fps then back). When I turn off fps limiter it functions fine.