Windows 7 SP1 x64
Core 2 Quad Q6600 @ stock 2.4 GHz
8 GB RAM
GeForce GTX770 2GB with 384.76 driver
I already posted once that I have very low FPS in GRIP compared to even other UE4 games (Redout), and I played GTA V and DOOM (2016) on max settings with no problems on this very rig, even though the CPU is old as hell.
Anyway, I've experimented some more and found out something interesting.
Measured in 4 lap normal races at FIC Outpost (it's pretty much the same on every other track, with values offset by about 1-2 up or down depending on track), using two sets of settings:
1. LOW = 1920x1080, lowest possible settings for everything (OFF if applicable).
2. HIGH = 1920x1080, AO on, motion blur and sharpening at LOW, FXAA antialiasing, all other settings at EPIC.
1. LOW, 10 car race: 30 FPS at the start of a race, then pretty much 19 FPS all the time.
2. HIGH, 10 car race: 30 FPS at the start of a race, then pretty much 18 FPS all the time.
3. LOW, 6 car race: 35 FPS average, max: 42, min: 27.
4. HIGH, 6 car race: 32 FPS average, max: 40, min: 25.
And here's what I get with in a race with no opponents (time trial):
5. HIGH, 60 FPS average, max: 80, min: 40.
TL;DR: there's 1-2 FPS difference between the highest and the lowest settings. What really affects the performance is the number of cars on track.
My guess is that AI code is to blame for the slowdown, but a 10-player online race is needed to test this theory.
Two more interesting facts that I don't really know what to make of:
1. If I turn on slowmo in a 10 car race, FPS magically jumps to around 30 (regardless of graphics settings) and stays there until I turn it back off.
2. In 10 car races, it's always 30 FPS at the start of the race, and then it drops to and stays around 18.