I have used Linux a bit for research through the years but this is my first time messing with GPU things on my Ubuntu machine so a lot of this is new (I set up dual boot after recent frustrations with Windows).
On Windows 10, by default my system allots 24GB of RAM to shared GPU memory, allowing for a total of 32GB of memory that the GPU can use. It seems that on Ubuntu this is not the case, and I have not been able to find any sort of setting to change it. It seems to be fixed to what the hardware has available to it: 8GB.
Some relevant system specifications:
-Ubuntu 22.04.2 and Windows 10 installed on separate SSDs
-ASUS ROG B550i motherboard with a Ryzen 5 5600x CPU
-NVIDIA 3070 GPU, driver version 525.125.06, installed "using NVIDIA driver metapackage from nvidia-driver-525" from Software & Updates... I went with these "suggested" ones since I had issues installing drivers in the terminal (blank screens when booting, only one monitor would work, etc)
-48GB RAM
Obviously I could just limit myself to only use 8GB (which I am presently doing), but given all the other RAM available, I don't see why I can't have a setup similar to Windows. There are no BIOS settings to change shared video memory, and nvidia-settings (nvidia x server settings) evidently has no option either.
After too much time wasted web-searching, I wasn't able to find anything relevant. I even asked everyone's favorite language model and it just said to disable efifb in the grub config, and I don't understand at all how that will help. I would be very surprised if there is no way to do this, given Windows can do it out of the box.
