Pressing "F" on your keyboard will enable the FPS/Network Display box, which shows your graphics performance in Frames Per Second, along with your Network connectivity detail display. The FPS/Network Display box appears in the upper right-hand corner of the screen when you're in-car and on the track:
The FPS/Network Display box shows you four values:
FPS (graphical frame rate in Frames Per Second, or FPS)
L(Latency, or data transmission delay between your system and the iRacing server)
Q (Quality of the connection to the iRacing server)
S (Service, showing the state of Synchronization between your computer and iRacing)
P (Page fault meter, indicates if you are experiencing system page faults related to memory settings)
F (Force Feedback of the steering wheel)
The "FPS" indication at the top of the display is a numerical value that represents your frame rate in Frames Per Second (FPS), which is a reflection of your graphical performance.
The "L" portion is a bargraph that represents your latencyof your connection, or the time delay for data transmitted between your PC and the iRacing servers. This bar can vary in length and in color -- a shorter bar length or a green bar indicates a low latency or delay, and if this bar turns red that indicates that your latency is reaching an unacceptable acceptable level. When you see a red bar here, this is an indication that the latency has dropped to an acceptable level, which may result in a disconnection from the iRacing server.
The "Q" portion is a bargraph that represents your connection quality, and this bar can display varying colors -- a green bar is good, yellow or orange means less than ideal connection quality, and it will turn red if your quality is dropping below an acceptable level. When you see a red bar here, this is an indication that your connection may drop and you may be disconnected from the iRacing server.
The "S" portion shows the service/sychronization state, or the "skew" of your connection to the iRacing servers. As with the "Q" bar, a green bar is good, yellow or orange means less than ideal synchronization with the iRacing service, and it will turn red if your synchronization is dropping below an acceptable level. When you see a red bar here, this is an indication that your connection may drop and you may be disconnected from the iRacing server.
The "P" portion is your page fault meter, which indicates if you are experiencing page faults because your system is using your disk drive to make up for lack of available physical RAM. If you are seeing a solid yellow or red bar in the "P" meter, you may be experiencing reduced video performance -- to eliminate the yellow or red bars, the easiest solution is to lower the GPU Video Memory slider (move it to the left) in the advanced graphics options to make the simulation use less RAM. If this doesn't work you may benefit by adding RAM to your PC. Other processes and services running on your PC also use RAM, so it can help to reboot your PC and close down as many application as possible before running the simulation - to free up as much physical memory as possible.
The "F" portion shows you if the wheel is clipping and at maximum force even though the demanded force is higher than that. The idea is keep the F so it is rarely in the red. Applies to controllers that have force feedback feature.
If you have:
CPUMeter=1 ; Include the sim-thread's CPU usage in the L/Q/S meter group?
enabled in app.ini you will get 3 more bars:
C - CPU usage for the physics threadR - CPU usage for rendering threadG - GPU usage (includes some driver time, we ask for how long from the driver starting a frame until driver tells us the frame has finished)
The bars are calibrated for 60fps.