egpu

est your browser use which gpu?

https://alteredqualia.com/tmp/webgl-maxparams-test/

https://egpu.io/forums/pro-applications/chrome-browser-not-using-egpu/







https://support.apple.com/en-us/HT208544

2. Select the app in the Finder. Most apps are in your Applications folder. If you open the app from an alias or launcher, Control-click the app's icon and choose Show Original from the pop-up menu. Then select the original app.
3. Press Command-I to show the app's info window.
4. Select the checkbox next to Prefer External GPU.
   
5. Open the app to use it with the eGPU.

You won't see this option if an eGPU isn't connected, if your Mac isn't running macOS Mojave or later, or if the app self-manages its GPU selection. Some apps, such as Final Cut Pro, directly choose which graphics processors are used and will ignore the Prefer External GPU checkbox.

Chrome browser not using eGPU

https://egpu.io/forums/mac-setup/catalina-not-using-my-blackmagic-egpu/

In multi-GPU systems, Chromium automatically detects which GPU should be used for rendering (discrete or integrated). This works 99% of the time, except when it doesn't - if a unavailable GPU is picked (for example, discrete graphics on VFIO GPU passthrough-enabled systems), chrome://gpu will complain about not being able to initialize the GPU process. On the same page below Driver Information there'll be multiple GPUs shown (GPU0, GPU1, ...). There's no way to switch between them in a user-friendly way, but you can read the device/vendor IDs present there and configure Chromium to use a specific GPU with flags:

$ chromium --gpu-testing-vendor-id=0x8086 --gpu-testing-device-id=0x1912

...where 0x8086 and 0x1912 is replaced by the IDs of the GPU you want to use (as shown on the chrome://gpu page).

How to specify command line flags

Let's say that you want to add two command line flags to chrome: --foo and --bar=2.

 Mac OS X

1. Quit any running instance of chrome.
2. Launch /Applications/Utilities/Terminal.app
3. At the command prompt enter:
   /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --foo --bar=2

Don't think of it too much.It's the NVIDIA driver.Probably is more restricted then in windows os,even under windows WEBGL is accelerated by your iGPU.You can visit this website(under Windows),go all the way to the bottom and you'll see something like that: ANGLE (Intel(R) HD Graphics 3000 Direct3D11 vs_5_0 ps_5_0) which means that the iGPU does most of the work.Nvidia's excuse is that if they allow their driver to accelerate  the browser on switchable graphics systems it will waste too much battery(i guess here is a good place to say: F#@%K NVIDIA).
You can try these flags combined with the the two mentioned above to see if it's possible to force it,if it's not you just have to leave with it: --supports-dual-gpus  --ignore-gpu-blacklist  --disable-gpu-driver-bug-workarounds  --use-angle=gl   --enable-gpu-scheduler
P.S. Remember to insert two(2) hyphen characters(dash) before the command line.For some reason when i post it here it's showing only one.

not sure if you still checking the replies here but if you do i think i found the proper command line switch:
--gpu-active-vendor-id=
--gpu-active-device-id=

 --gpu-active-vendor-id=   --gpu-active-device-id=

Unfortunately i can't test it due to being stuck with 378.92 driver which is the last one that properly accelerates Chrome with my eGPU  so try it and let us know.

For macOS(ONLY), run Chrome with "--force_discrete_gpu"  argument....
....(also try "--force_discrete_gpu=1" or "2")
If it doesn't work try  "--gpu-driver-bug-workarounds=48" or "228" 
If it doesn't work try  "--enable-features=force_discrete_gpu"
Post some feedback guys and good luck. 🙂
P.S. For Windows: NO LUCK...YET  😕