This tweak is inspired by the one created by VIT774 (link to original thread at the end).
Before we get started, this is NOT a “hack” or “cheat”.
Forza Motorsport uses server side checks to make sure you aren’t altering anything to gain an unfair advantage.
I can confirm this because during testing, I put in certain values and the game would load, but it wouldn’t let me log in. If I returned the original values, the game let me log in without issue. So, there is limit on what you can adjust on your (the client) end.
Now, the files you’re going to want to change can be found in the following locations:
\Forza Motorsport\media\pcfamily\renderscenarios\High
\Forza Motorsport\media\pcfamily\renderscenarios\Ultra
\Forza Motorsport\media\pcfamily\renderscenarios\Visualtarget
Inside these subdirectories are the following files:
cartheater.xml
cinematic.xml
focusspace.xml
frontend.xml
global.xml
greyspace.xml
pitting.xml
race.xml
There are others, but these (above) are the files we’re going to be editing.
You can edit these files with Notepad, but I recommend using Notepad++ (free!) since it’s an improved version of Notepad designed for coding/editing/scripting.
Open one of the files listed above and look for…
<ShadowMapResolution value="4096"/>
Change 4096 to 2048.
You want to search and replace every instance of where shadow maps, or other textures are listed as “4096” and change it to “2048”, or lower. Do this for all of the files listed above.
What this value does is it tells the game to use a shadow map (texture) at 4K resolution. Changing it to a lower value tells the game to use a lower resolution one at 2K. Presets like “Low” and “Medium” already have lower values ranging from “1024” down to “64”. You can try different values in lower multiples of two e.g. 512, 1024, 2048, etc.
Shadows are one of the most graphically intensive things to render because they are everywhere e.g. cars, trees, trackside buildings, spectators, etc.
Having each one use a texture at 4K is going to quickly eat up VRAM, but also require more hardware processing power. Consider the power needed when there are 23 other AI cars on track, each casting a shadow at 4K! That’s a combined 96K texture resolution just for the cars alone!
More importantly, I think the underlying reason this tweak improves and smooths out performance is because the 4K texture that is being called is NOT compressed properly? Meaning, it may actually be well above 4K, and that might be one reason why the game stutters because it’s “bottlenecking” the rendering pipeline?
IF this is true, this may be one big reason why this game has wildly differing performance across multiple hardware?
Most people who don’t have performance problems never list what resolution they’re playing at, or their hardware. If they’re playing at 1080p, at the “Medium” preset, on moderate hardware, of course, they should have smooth performance since the shadow map being used is only at 1024 resolution which is very low by today’s standards.
I have a AMD 3700X paired with a Radeon 6800XT with 16GB VRAM.
I run the game at 4K, 60fps on a 55" HDTV.
The individual files I altered were under the “Ultra” and “Visualtarget” subdirectories.
If you have lesser hardware, you probably don’t need to alter anything since the default values are already low. However, you may find lowering them even more might help with overall stuttering and/or fps drops around certain tracks?
Let me know if this helps because like I stated above, this not only smoothed out my overall frame pacing, but it nearly eliminated the fps drops at certain places on tracks that may be due to clusters of large shadows e.g. buildings, foliage, spectators, cars racing by, etc.
This tweak allows me to run the game with SAM (Smart Access Memory) enabled (Rebar for Nvidia users). I could never do that with the vanilla game until after this tweak.
The original thread by VIT774, that inspired this tweak:
