I'm getting a lot of questions on how to get started on mGPU, I should probably make this a separate thread (and will probably do so) as a teaching moment, but I also understand that savvy folks want to know "how" to do it.
So will repost in here some of mu other posts/treads from other sites to try and provide more central start.
While embarking on
mGPU, and not go straight to how to enable mGPU in UE4 and UE5, easier examples are
Strange Brigade, Ashes of the Singularity and Gravity Mark as they work without too much fussing and have friendly menus to get you there. GravityMark is a great tool to hone and optimize you’re setup.
Gravity mark should be your very first stop on mGPU:
GravityMark GPU Benchmark
gravitymark.tellusim.com
GravityMark GPU Benchmark
gravitymark.tellusim.com
Now, please know that what comes next is important:
… but the OS optimizations (HAGS, GPU per affinity, ReBAR etc) and the driver basics only (no GeForce Experience, none of the driver optional install components that interfere and importantly, → nv container CAN NOT be running in the background)
Example, I do not have any of that in the background, runs faster and more stable. I don’t use the nvidia app or the control panel, I integrated the inspector and profiles instead on my right click:
Nvcontainer / nvidia service breaks many mGPU attempts
I have it turned off in services (manual)
I can’t seem to included an image in this message editor so I will provide that setup in your main thread.
I use a right click shortcut to control the set up but if needed I use the start stop shortcuts
For starters -here is
my desktop right click:
I disable the NVContainer / nvidia service but if I ever need to get to it I start and stop it with shortcuts:
(yes, all my tiles are orderly and well behaved and are transparent without any vendor or MS added colour, I also have no ads running
for tile transparent background colour modify the xml
with:
BackgroundColor=‘transparent’/>
…easy enough, just try it
nvcontainer set to manual in services as such:
start stop shortcut commands are easy:
net start NVDisplay.ContainerLocalSystem
net stop NVDisplay.ContainerLocalSystem
you may want to disable Shader Cache in the CPL, for me, it breaks all my mGPU or at least reduces the performance significantly, the CPL Shader Cache has a negative effect on ALL my games
If you are on server 2022 or preview 2025 data center as workstation, you can prevent mitigations in
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
“FeatureSettingsOverride”=dword:00000003
“FeatureSettingsOverrideMask”=dword:00000003
Also disable any mitigations in BIOS (your choice)
I realize some folks don’t understand mitigations and have a rubber stamp response, but I leave that choice up to you, these are my choices.
next
you must have resizable BAR on in the BIOS and you need to set the Resizable BAR to “unlimited” ( I believe the switch choice is “32” in the setting.
in windows you can use (if your hardware is capable) the :
ReBarState.exe
Driver:
the driver itself should only include these things in the downloaded driver and remove so that this is what is left:
and modify the bottom of the CFG file so that the three lines under the eula are gone, like this:
ONLY then do the exe setup
for pre 2015 games that use physics you should install the separate concurrent standalone exe from nvidia.
PhysX-9.13.0604-SystemSoftware-Legacy.exe
etc etc etc
yes, lot’s to do to have a fast stable windows system, I could not get it to work under win 10 or win 11, but it works under server 2022 and server 2025 (I use windows server 2022 or 2025 data center as a lean Workstation)
Then starts the ramp to some of the more involved steps
the next “easier” game to set up is Civilization IV and also a good introduction to what lies ahead.
step 1: DO NOT USE STEAM VERSIONS OF GAMES, only standalone versions without a third party check in “rent to own” games. Games that the version lets you launch the game from the real exe in the game folder.
Please include the correct switches in the property of the launcer for the executable, these have to be enabled here first.
Ashes of the Singularity:
Civilization IV, you’re goal is to enable this check mark without SLI or NVLink:
in in Fraxis, in the graphicoptions.txt
set these changes:
;Set DX12 compute queue usage on (1), off (0), or platform default(-1).
EnableAsyncCompute 1
;Enable DX12 split-screen optimizations for multi-GPU systems. On (1), Off(0), or platform default (-1) [Platform Default is OFF, but may change in the future.]
EnableSplitScreenMultiGPU 1
[Video]
;Experimental rendering modes
RenderMode 1
;Experimental resolve modes
ResolveMode 1
and save the file as “read only”
you can also go into the other config files and manually set the amount of threading for cpus and other features, it scales well.
I have to look up which version I have as one of the updates from Fraxis
broke all those GPU and CPU perks.
So, ready to start the journey to faster more stable and enjoy your PC again?
Then you can proceed to other titles like Chernobylite and get mGPU scores like this with max / ultra raytracing at 4k and NO DLSS and no FG:
Disclaimer:
I only toy with this stuff as a hobby, I’m more of a cars, motorcycles, swiss watches, fountain pen, CDs and Vinyl, pistols kinda guy. And so I may not convey in the appropriate vernacular and lexicon of geek-speak. It probably doesn’t help that English is not one of my primary languages.
Anyhow, it FEELS as if nvidia and MS deliberately make it complicated, I merely look for solutions around the obstacles. if you’re interested I may post more on the MS server as your personal PC OS and how to make it be fast, private, stable and able to do all the things I do.
some stuff is complex and some stuff is simple like use the HOST file to give you browsing and your day to day life more privacy. See, I’m of the opinion the OS works for me and that the OS is not a way of life. Whenever I see Microsoft or Google say that the keep your data private, my first thought is “how do I keep my data private from YOU (MS,Google, Apple, etc)?”
Anyhow, that’s a separate rant
