60+ Car Sessions: why am I losing 40 seconds per lap while spectator mode runs Fine?

blasotto

Member
This topic has already been discussed many times, but I still keep wondering about one thing.

Why is it that during an online session with a large number of cars on track, in this case around 60, I end up lagging and losing so much time per lap?

At Le Mans, I noticed that I lost as much as 40 seconds in a single lap while driving exactly as usual: same racing lines, same braking points, and no significant mistakes. My normal pace is around 4:05, so a gap that large is huge and hard to explain.

The strange thing is that it's not just the lap time. When this happens, the whole world around you seems to slow down. Cars passing by start lagging, shaking, and moving erratically, as if the synchronization between clients is completely off.

To make the test as fair and clean as possible, I started from the pit lane and therefore from the back of the field, specifically to avoid causing any issues for the drivers ahead. Despite that, the race still ended badly: during one of these lag spikes, a car that was lapping me hit me at full speed, and I was effectively taken out of the race.

What makes this even more confusing is that after I retired from the race and switched to spectator mode, everything seemed perfectly smooth. Watching the other cars racing, I didn't notice any lag, stuttering, or erratic movements at all. If the session can run smoothly while spectating, why does the problem only appear when I'm actually driving?

Has anyone else experienced the same behavior in heavily populated sessions? Is this a netcode issue, a server-side problem, or is there some setting that could be affecting this?
 
This means your CPU can't keep up with what the game needs on the main game thread. When you're driving it's calculating your car physics plus the AI and some other stuff, and your car physics is very demanding.

When it can't calculate everything in time (which happens 400 times a second) the game will go into slow motion.

This could be your hardware just isn't capable enough (raw CPU power), you could be running out of ram/vram which slows things down, or you have other processes that are taking excessive CPU and making this happen.
 
@blasotto You didn't give us details about your setup.

I have a Ryzen 7 5800X3D with 32GB of RAM and a RTX4070 Super and with everything at its max I have never encountered anything like it
 
The fact that it makes you run slower is very unusual.

In something well developed/coded it should not happen.

Maybe set down AIs performances, restrict their number but don't affect player behaviour as much as possible.

LMU, like rFactor2 have a very unique set of processing "priorities", i would say, and consequences are often weird.
 
The fact that it makes you run slower is very unusual.

In something well developed/coded it should not happen.

Maybe set down AIs performances, restrict their number but don't affect player behaviour as much as possible.

LMU, like rFactor2 have a very unique set of processing "priorities", i would say, and consequences are often weird.
No physics cycles are skipped, so not keeping up produces slowmo. Same as rF2 indeed.
 
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