Extreme lag with multiple AI vehicles

When you have more than two AI vehicles, the game becomes extremely laggy. In this case, I was driving the D15 Dually and had two AI controlled Grand Marshalls set to chase the player.
At the time of the screenshot, my GPU monitor was at 0% and my CPU meter was reading 42% or less on each core, and the game was running at roughly 1 fps.
It's obvious 25 fps isn't correct, and the CPU monitor is about where it usually is, but typically my GPU meter reads 99% (dat bottleneck ).
Pressing 'J' to disable physics drastically improves the framerate.

 

You need a good cpu to run 3 cars. Most people can't even run 2 cars without suffering from extreme lag. I myself can run up to 4 cars with 50-60 fps in grid map.

Post your PC specs and we'll see if that lag is normal. It proably is, 3 cars require a 4 core intel.

And those 25 fps ARE NOT the fps of the game but of the car's physics.

 

I noticed about a 20% CPU usage per car.
As soon you get to much CPU usage (80%+)then the gpu usage goes down too resulting in low frames.

 

The highest my CPU usage has gone (that I've noticed) was 92% on one core. Average seems to be in the high 70's with these three vehicles all next to each other.
(For some reason they dipped a little lower in the screenshot)

I do have a 4 core Intel which can run 3+ cars otherwise.

Specs:
Intel i5-2400 Quad core, 3.1GHz
Nvidia GeForce GT520 (I could use a better GPU)
8GB DDR3 RAM

All of my graphics settings are on Low and my resolution is 1440x900 in windowed mode. Grid map runs pretty fast on those settings.
CPU is never my problem when it comes to games, my GPU is almost always what is holding me back.

Ah, that number has always puzzled me.
Is there anywhere I can access the actual framerate?

 

I can run 3 AI cars with no noticible drop in performance. My brother, with his dual core, cannot run any AI cars. You need a pretty powerful CPU to handle multiple cars.

 

Control + F.

 

Me too 'cause it goes sometimes over 1600 fps

 

In a previous thread I made, a person said that 1 car = 1 Physical core. The dev's then confirmed that. Most PC's have 4 Cores. If you don't know how to check go to "Performance" tab in the task manager. If you don't know how to get into the task manager, this will help you: http://lmgtfy.com/?q=How+to+open+Task+Manager

 

I'm still pretty sure this is a bug. There's no reason I can run 3 vehicles alone, but not 3 vehicles with AI, unless of course the AI coding is extremely inefficient with system resources.
I notice no drop in performance with 2 vehicles and AI, it's just when there's 3.

So I should be able to comfortably have four cars as I have 4 physical cores.

 

Well, if the cars are moving then there are more physics calculcations, that might be the problem. But I have to say I didn't feel any lag at all running 3 cars with AI enabled.

 

So I guess when the devs add real gameplay (racing), the game is going to be unplayable for most people?