New DirectX 12 Feature Improves Performance With Simultaneous VRAM Access From CPU & GPU
New DirectX 12 Feature Improves Performance With Simultaneous VRAM Access From CPU & GPU
GPU Upload Heaps works in conjunction with Resizable BAR to allow CPU direct access to VRAM at the same time as GPU.
Games are about to get another performance boost: a new feature from DirectX 12 called ‘GPU Upload Heaps‘ allows for CPUs to directly access the GPU VRAM even when GPU is actively accessing it. This simultaneous access negates the use of additional system RAM to copy excess data in the event of waiting for GPU access, which should mean lower RAM and CPU utilization.
The principle for this feature is pretty simple. Conventionally, when CPU needs data from GPU VRAM, it needs to check whether GPU is actively using it in that clock cycle, and waits if the VRAM is being utilized. Data gets stored temporarily into system RAM, however that incurs a minor performance penalty since you’re moving data across systems. With this feature, CPUs can simply grab the data from VRAM without the need to wait or store the data for compute and calculations, cutting down performance overhead.
End users simply needs to enable Resizable BAR (or Smart Access Memory if you’re using AMD systems) provided that the hardware supports it. The feature is already available on the driver-side, however since this is fresh from Microsoft’s oven, don’t expect games to immediately use the feature. It may take at least months or even a year or two before such feature shows up in new titles; and it remains to be seen for developers whether such feature can introduce noticeable performance improvement overall on existing titles.
Source: Tom’s Hardware
Pokdepinion: This should help with systems on 16GB of RAM, new games these days are beginning to fill up those pretty quickly.
