a) Please make sure you're computer is up to our system requirements which are listed HERE
b) Please make sure that you have all of your Windows updates installed.
c) Please make sure that you have the most up to date drivers for your sound and graphics cards.
Please remove any GPU overclocking
Use any 'debug' modes (example: Debug Mode on in the NVidia Control Panel) to reset GPU.
d) Try and run the SIM with minimum graphics settings. Start with turning off Shaders and Shadows.
e) Try running the SIM in Windows Mode (vs. Full Screen)
f) Edit the app.ini file NumSound Streams setting to 12 (the minimum)
g) Turn off VSynch in your graphics card setting control panel
h) Lower the VidMemToUseMB setting in the appropriate \Documents\iRacing renderer file
i) Go to Task Manager...Processes Tab. Right click on iRacingService.exe...Set Priority and make sure the priority is set to Normal, Above Normal or High
j) If you are connecting through a router, please try and bypass your router and connect your PC directly into your modem. If this works, you will need to either update the routers firmware, add the .exe's to the router's exception list or consult the router manufacturer.
k) Go to My Account and in the Preferences section at the bottom of the My Account Home Page, change the Connection Type to the first one listed: "DSL, Cable, Fiber, 128K or faster - Supported".
l) If you are still having issues, please contact support@iracing.com