High GPU usage issues with Unity Games: (includes Fantasy Grounds)

[Laerun]

This issue has been said and addressed several times before in the House of Healing.
This potential issue is also not just a Fantasy Grounds issue, it is inherent to the Unity engine itself.
Video cards and their respective drivers, card settings, and computer builds differ and vary in these potential areas.

To help address the high GPU usage issue in Unity games, like Fantasy Grounds Unity, caused by Unity Engine's default behavior of rendering as many frames as possible, consider these approaches:

Limit Unity Frame Rate: Cap frame rates to reduce GPU strain. Search "limit unity fps" for scripts and settings.

External Frame Rate Limiting: Use your video card's software for this purpose.

Frame Rate Limiting Tutorial
Fantasy Grounds Unity Guide: Offers specific advice for FGU, including driver settings and commands.

Fantasy Grounds Unity GPU Usage Suggestions
Combining these methods should or might help mitigate high GPU usage in Unity-based games.

YouTube tutorial on Frame Rate Limiting in Unity: https://www.youtube.com/watch?v=DT-ig6dd82U

Unity's documentation on vSyncCount: https://docs.unity3d.com/ScriptReference/QualitySettings-vSyncCount.html

Fantasy Grounds Unity Troubleshooting Guide for Reducing GPU Usage:

https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/1638006786/Reducing+GPU+Usage

Updates:

The Fantasy Grounds platform has been set to 60 FPS Vsync settings by default now.

As of August 2025, some of the video memory CPU/GPU usage issues have been addressed with Unity updates.

Source:
Unity 6 is here: See what's new https://share.google/0SU6a4XSKuJ6bYOD4

[Nick Frost]

I really think this should be a Sticky either here or in the House of Healing. I've been troubleshooting this issue on a case-by-case basis when players complained about "FG being slow" or "using too much GPU", and for some reason never ocurred to me to just compile the links with the relevant info :D

[Swissman65]

One neat trick that helped me find my issue :
Since I use FGU on Steam, you can add an FPS counter on any launched game/software.

Once I saw that my FPS, while in FGU, jumped around 1500-2000 that confirmed that capping my FPS would be the fix!

[Morenu]

Just Curious, this video states that the game maker can lock the FPS, why not just do that at a level that works for FGU?

Lock FPS (https://www.youtube.com/watch?v=0D_snAEh7pw) its in the first 3 minutes. I can't imagine that FGU would need more than 60fps. and you can adjust as needed with a new release.

[Moon Wizard]

Our default behavior is to set frame rate to match refresh rate of monitor (which typically is 60-120, though some monitors scale higher). You can change to having the application set a fixed 60fps by using "/vsync 0" chat command.

However, given that we see people that have systems running at 1500-2000; that means that the graphics driver is overriding the default behavior limits somewhere in the graphics pipeline.

Regards,
JPG

[Eddiesuxnutz]

I've tried all of these fixes, and none of them seem to work. Tonight, not only did I crash, but my friends did, as well. It's not a simple crash either - it takes Discord, etc with it. I made a topic about it months ago, but it seems to now be spreading to people playing, not just me as the host.

I play plenty of other unity games like Hearthstone etc (and I edit things in Unity from time to time) and never have this issue.

[Moon Wizard]

If it's taking down other applications, then that usually points to some issues with hardware/drivers as Windows prevents applications from affecting others directly (with the exception being shared drivers).

The difference between other Unity games and FG is that we let you use your own graphics, instead of graphics that have been fixed to very specific sets and heavily optimized for managing memory usage and performance. That's why we provide guidelines for the kinds/sizes of images to use in FG to get the best performance and avoid issues. These guidelines are applied to any product that is submitted for sale on our web store.

* What resolution are the images you are using for maps?
* Were you able to verify that the frame rate was locked at 60 fps when switching to /vsync 0? (You can use the built-in Windows Game Bar to help measure FPS.)

Regards,
JPG

[Moon Wizard]

Also, if you can provide a zipped up copy of your campaign folder and which maps you were using, I can pass along to our image feature developer to look at.

Regards,
JPG

[Trenloe]

@Eddiesuxnutz - so is the main change from your previous thread on this that players crashed as well? Did everyone crash or just some of the players? Did the crash occur when a specific action was being performed, or a specific map was being used?

As an FYI for others looking to help, here's a reference to your previous thread: https://www.fantasygrounds.com/forums/showthread.php?79833-FGU-crashing-everything-on-my-PC

[Laerun]

@Eddiesuxnutz - so is the main change from your previous thread on this that players crashed as well? Did everyone crash or just some of the players? Did the crash occur when a specific action was being performed, or a specific map was being used?

As an FYI for others looking to help, here's a reference to your previous thread: https://www.fantasygrounds.com/forums/showthread.php?79833-FGU-crashing-everything-on-my-PC

How big or large are the image dimensions that you are sharing with your group in your campaign? Sometimes large images and complicated maps can become troublesome. Are you running any extensions, things that impact maps or the Combat tracker?

Also, did you ever find out your system temps after playing for awhile?

[ottoharkaman]

Wow this program runs really hot, I was worried I wouldn't be able to use it. Talked with the AI after I noticed there was a boot.config file in the FantasyGrounts_Data folder. AI wrote me a small script to use in the config file that should keep things from getting so hot.


gfx-enable-gfx-jobs=1
gfx-enable-native-gfx-jobs=1
force-gfx-job-worker-count=1
target-frame-rate=30
graphics-api=Direct3D11
wait-for-native-debugger=0
hdr-display-enabled=0
gc-max-time-slice=3
build-guid=

I guess its an individual number letter sequence in (build-guid=) left mine out.

Seems to work on my laptop not so much on my older Acer all in one desktop, haven't done enough testing yet.

[LordEntrails]

Wow this program runs really hot, I was worried I wouldn't be able to use it. Talked with the AI after I noticed there was a boot.config file in the FantasyGrounts_Data folder. AI wrote me a small script to use in the config file that should keep things from getting so hot.

I guess its an individual number letter sequence in (build-guid=) left mine out.

Seems to work on my laptop not so much on my older Acer all in one desktop, haven't done enough testing yet.
You might have better consistency across platforms using the commands within FG. See:Reducing GPU Usage - Fantasy Grounds Customer Portal - Fantasy Grounds (https://fantasygroundsunity.atlassian.net/wiki/spaces/FGCP/pages/1638006786/Reducing+GPU+Usage)

[ottoharkaman]

Thanks I will check it out

The vsync didn't help on my old Acer, Unity overpowers older intergrate graphics card computers, seems to be the case.

[KILLGORE]

I had this happen a while back where sometimes the dice roll .wav file would crash discord and FG. I had to reload everything after a while it went away. Dont know what it was but I can tell you it would only happen when I was using the audio output on the HDMI or DVI cable and not if I was on my headset audio. I think it might have been a driver issue caused by the dice roll sound in FG. All gone now thank Tyr. I have a pretty high power desktop so it wasnt a graphics thing for me but sound. Thing is HDMI and DVI audio is over the graphics card drivers. I was told there was a sync timing for whats being shown on the screen vs whats being heard and when the dice rolled it crashed some audio wav file associated with FG and when it gets something it doesnt like it crashes. Im not sure its above my paygrade, but windows event viewer showed some kind of wave file was the culprit. This was a couple years ago when unity was first out. No issues today.

[ottoharkaman]

Interesting I wonder if the developers saw my post. I see with this new update they added gfx-threading-mode=6 to the boot.config file
I think they fixed the multi-threading with the integrated graphics card before this cause I wasn't get an overheated cpu.

This was the config I was using before

gfx-enable-gfx-jobs=0
target-frame-rate=30
graphics-api=Direct3D11
wait-for-native-debugger=0
hdr-display-enabled=0
gc-max-time-slice=3
build-guid=

[Moon Wizard]

We upgraded the Unity engine to the latest LTS version provided by Unity, which is why the config is different. I'm glad to hear that it helped. We were hoping that upgrading to the latest version would help (which we try to do each summer when a new engine is available).

Regards,
JPG