NVIDIA Optimus for Desktop PCs

I think it was Linus Sebastian (Linus Tech Tips) made a video about using a similar method to Optimus to run apps on the dedicated GPU but displayed through the CPU integrated graphics, it was done using old mining cards (Nvidia ones) that had no display outputs. So it is possible but the method used to successfully do it are a bit involved and probably are not worth the effort beyond experimenting.

Helmut said:

The video outputs are separate, how are you getting around that, perhaps you had better show the Task Manager View of both.

I suspect what you are actually using is the iGPU.

The graphics settings you mention are in Windows 10 now, but that is only a repeat of what is available in the Nvidia Control Panel. That is not new and was available in Windows 8.1 for sure.

Optimus is where the graphics card renders the 3D graphics and then pushes the rendered data over the IGP to the display like an overlay.
Optimus uses proprietary compression which gets more data throughput on smaller PCI busses such as 2x or 4x connections. This is why it works on external GPUs that connect via thunderbolt or PCIe connections available even on old pcie slits used for wifi adapters before m.2 was introduced.
Optimus requires specific drivers or profile on the driver to enable it. Because Optimus by default is configured on laptops and not on desktops. It may be required to manually configure the ini file to detect your desktop GPU as a dGPU found in laptops or mobile version. It really has to do with the configurations found in the profile though of the ini file whats applied based on the hardware detected.
This can be manipulated. This is what was required back in 2011 on Windows 7 when I took a laptop running a 3rd gen i3 and hooked up a external GPU via a custom cable I had built to connect to my pcie wifi port underneath and outside of my laptop. I even did this whil I was deployed in Kuwait from a shared room. I read about how to modify INI files and tracked Optimus from its beta stages. I even still have copies of the beta drivers I modified to make my external GPU work.. So honestly it has nothing to do wither its a laptop.. purely to do with do you have a intel processor, windows 7 or windows 10 and the right drivers that will support your hardware with optimus being enabled.
Hybrid config is not optimus.. You will know for certain if Optimus kicks in.. in my testing I could run FFXIV at only 6 frames without optimus because it was running on my IGP core. While with Optimus was a playable 30ish frames. Resident Evil 5 ran about 16 frames and almost 60 with Optimus enabled... all going strictly through the laptop screen, no video cables running from the GPU, just sat there on my desk being held up by card board box I taped to make a stand and an external Desktop PSU hotwired to provide power to my 16x PCI slot riser connected to a mini display port to a mpcie slot where wifi adpater hooked up...
To get the card and GPU to post back then I would hot swap my wifi card while in sleep with my GPU... and then grab that data gathered from the undetected device and then code it to the driver.

A Laptop is not much different then a desktop, yet the laptop screen is directly wired on board leveraging the IGP, allowing optimus to be used to push dGPU rendered graphics via the IGP bus on the CPU.
This why not all Laptops can support Optimus but nearly all desktops running in the same way should be able to.
The same would be on a desktop if you enable IGP and connect the display via the motherboard. Windows 10 from testing a while back seems to natively support external GPUs, but this would be if you connected the video connection to the GPU directly. While connecting to the computer and rendering a game while monitoring the GPU stats in task manager should show the dGPU working. For me this is only in theory because I haven't tested it myself on windows 10 with the same method this individual has. But I plan to as I recently purchased a 11600K which the Iris is know to have pretty good performance while supporting 8k resolutions.. My GTX 1080 currently does not so if I can run my connection through the mobo over display port to my Samsung Odyssey G97T then I should be able to get the full 240hz refresh rate at 1440p 32:9 while still leveraging the GTX 1080 power to render 3d on an overlay pushed through a fairly large pipe of bandwidth from the FSB back to the CPU and Display port. While in other circumstances like in a laptop and based on how you configure the profiles in the nvidia panel can use only the IGP or Iris GPU on the CPU Die.
I'm really thrilled about this because in my testing in the past on Windows 7 days, the results were amazing.
While back then I only tested on a cheap 300 dollar laptop, this time ill be testing on a graphics card that is truly amazing for its time in power with a FSB RAM and CPU that can truly push allot of throughput, which when running optimus that is a major factor in overall performance.
Here is the site I learned these tricks from back in the day and I used to be a major contributor as I published my own custom drivers back then:
DIY eGPU experiences | NotebookReview
You'll see a large array of systems using Desktop GPUs in optimus mode on windows 7.
Mind you windows 7 doesnt get security updates.. I would say get it working on Windows 10, and most likely can do out of the box standard drivers if setup right.
My entire statement above is if it doesn't work as expected then Make it Work!
All that is required is a Nvidia GPU, an Intel CPU with built in GPU on cpu. not external on board IGP... and the right drivers, in which also detects your GPU with the proper profiles to enable Optimus...
Sounds complicated... maybe.
I'll build my new system next week and start testing..
BTW this article inspired me to definitely test this out, Thanks for That!
I guess I was searching to satisfy an old past time curiosity.

Also for those wanting to use Quick Sync from intel dedicated GPU core then you need the GPU on CPU enabled.
This provides then all kinds of benefits rather than using NVidia hardware acceleration for transcoding, or video encoding/decoding. - Obviously not everyone cares about this but Nvidia actually sucks at this compared to Intel. Qsync renders excellent quality and performance. While most that care about quality will say Nvidia is fast but quality is horrible.

There are so many reasons to want a Hybrid/Optimus setup... Its a superior platform.. If you want dedicated GPU performance, then you just connect a display port straight to the dGPU but doesn't necessarily mean its better in all circumstances. I'm also very curious if after getting one GPU to work via Optimus can you add another just for physics processing... or to handle other tasks.. Hybrid it up ATW! But only if Optimus works. If Optimus is a no-go, then I'm going back to dedicated mode, but that's a last resort as based on this article and a few others seems like its working out of the box which is great news to hear.

I recall my beta testing days... Optimus used to render a splash screen which really let you know it was working lol... after hacking the beta drivers to work with my desktop GPU on my laptop then I hacked the driver more to ensure the splash screen did not exist lol... but then optimus was no longer beta and the splash screen went away on its own. Each time a new driver came out I would have to rebuild the ini to work for my system, that's the kind of dedication I had back then. For me it was a conquest to turn my PoS 300 dollar laptop into a gaming machine unprecedented by any laptop lol. It was an amazing feat to say the least.
Check the Website out you'll find an old school site with numerous people with similar ambitions I had. So its nothing new, and one of my main reasons for commenting was the idea that Optimus doesn't work for Windows 7 lol...
If you really are using Windows 7 still... then just refer to notebook review and check on how to modify Ini drivers guide. I'm sure you put enough effort in you'll get it working. I promise. Yet I think I saw someone else mention... it's probably not worth the effort... I mean probably not if you don't care to get the most out of what your seeking... and is if you are.
It's not that hard. Take the time to read and you can find the answer to nearly anything.. If you cant find the answer then you search at the core and find the answer for yourself. For me its testing it for myself.. All I had to do was read about how optimus worked and then started theorizing and had to test it for myself. Search for answer on how to possibly do what I needed to until I figured it out. Ambition will get you pretty far, and thinking its practically impossible will get you no were.

With that being Said,
Happy Testing!