Driving around a track on my own I get pretty reasonable performance, around 150-200fps. However on race start, with cars all around me, the performance completely breaks down to as low as 30fps. Judging by MSI Afterburner, this issue is caused by the GPU being maxed out, the CPU is idling around even with all the cars. Some performance loss is of course expected with more cars around, but this seems a little to drastic. I already reduced opponent detail to low and disabled soft shadows, but neither has much effect. Reducing the number of visible vehicles works, but results with cars popping in and out of existence. Is there any other kind of tweak to enhance performance? Any kind of LOD level bias that I could tweak to have things run faster without having the car turn completely invisible? Specs: Intel Core i7 2600k, AMD RX480 4GB, 16GB RAM, Windows10.1
AMS is still 32 bits, so it will never use all of your 16Go unfortunately… (But it is good to have more RAM for other processes! ) That will always be a limitation with many cars. When you start the game from Steam, you can open the user guide: there are some really great advices for setting up your graphics in there, and get the most of your specs. Shadows have a pretty strong impact if you reduce them. I also noticed a performance improvement when I capped my fps: you don't need to have 150-200fps! Depending on the refresh frequency of your screen, try to cap at 144 or 75 or 60. I'm not sure it will be significant but it was worth the change in my case.
Have you increased the "visable cars" option in the display section? Default is usually around 9. Limit it to 19-20. Numbers in the high 20s or 30 can and will make the game lose frames, especially with the more detailed tracks (road side details such as buildings and pit area assets)
Running a frame cap at 120 or even better 150 fps is perfect for race sims as the frame time (latency) is between 8ms (120 fps) and 6ms (150fps) which makes wheel input latency almost non existent and fast frame times make for much smoother game play, even if you have a 60Hz monitor set up, like i do (3 x 2560x1080 in Nvidia surround @ 7880x1080 bezel corrected). Setting the GPU control panel to on render 1 frame ahead stops the GPU queuing far too many frames for the CPU to deal with and this helps with the latency too. Tearing doesn't always happen on modern monitors and gpus if you go over your refresh rate(like it used to on older gen hardware) but it can be tackled with somewhat by using prime numbers as your frame caps if you do see tearing.
You shouldn't be getting that drop in frames, i had around 150-200 on a gtx970 at 3968x1200 triples and I never saw it go below 100fps even in our league with 20 cars on the track, have you verified the game files?
