One issue is that even if you are using GTT (dynamically allocated memory), this is still limited as a percentage of total RAM. Eg, currently on my 7940HS, I ha

One issue is that even if you are using GTT (dynamically allocated memory), this is still limited as a percentage of total RAM. Eg, currently on my 7940HS, I have 64GB of memory, 8GB of dedicated VRAM (GART), and then a limit of 28GB of GTT - there is an amdgpu.gttsize parameter to "Restrict the size of GTT domain in MiB for testing. The default is -1 (It’s VRAM size if 3GB < VRAM < 3/4 RAM, otherwise 3/4 RAM size)", but I'm not sure what the practical/effective limits are.