All of them, GPU memory is fully virtualized in order if nothing else to easily support multiple applications running natively on it since GPUs aren’t used for

All of them, GPU memory is fully virtualized in order if nothing else to easily support multiple applications running natively on it since GPUs aren’t used for display & rendering only anymore where multiple clients could be simply handled solely by the composer. Most of the driver has also been moved into user space at least on Windows and MacOS I’m not fully versed in the state of the user vs kernel space display drivers on Linux these days. https://learn.microsoft.com/en-us/windows-hardware/drivers/display/gpummu-model https://learn.microsoft.com/en-us/windows-hardware/drivers/d... https://learn.microsoft.com/en-us/windows-hardware/drivers/display/iommu-model https://learn.microsoft.com/en-us/windows-hardware/drivers/d... For clarity applications that don’t know how to use virtual memory will still operate under segmented mode where they’ll access the physical memory directly however under Windows at least these days and for a while now even the segmented mode is emulated you’ll need to run your engine on bare metal completely to access physical memory directly via segment addressing.