Multi-GPU Rendering
UNIGINE supports Alternate Frame Rendering (AFR) technology allowing you to take advantage of systems with more than one GPU to accelerate rendering performance. This technology is supported for applications running on the following configurations:
AFR works by alternating frames between the linked GPUs; one frame is rendered by GPU 1, then the next frame is rendered by GPU 2, then back to GPU 1, and so on.Enabling Multi-GPU Rendering for Your Application#
AMD CrossFire#
- Open AMD Radeon Settings (right mouse click on Windows desktop):
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Select Gaming section:
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Open Global Settings
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Enable checkbox named AMD CrossFire and click Confirm.
NoticeYou may have to switch to the different GPU if you don’t see this checkbox by default.
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After a screen flash, open Gaming section again. Select Add -> Browse at the top right corner and browse for your application executable (*.exe).
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After adding your application click on it to view additional settings and change AMD CrossFire Mode option to AFR Friendly
NVIDIA SLI#
Follow these steps to enable AFR for your UNIGINE application.
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Open nVidia Control Panel (right mouse click on Windows desktop):
- Select Configure SLI, Surround, PhysX in the left menu;
- Enable SLI (select Maximize 3D Performance and click Apply):
Select Manage 3D Settings
- On Program Settings tab click Add next to Select a program to customize
- In the Add window, that opens, click Browse
- Via the file dialog select your application and click Open.
- In the Settings column change SLI Rendering mode to Force alternate frame rendering 2
Limitations and Recommendations for Use#
Please note, that with TAA enabled SLI / CrossFire will not give you 2x performance boost due to complexity of deferred rendering. In a worst-case scenario you can even get lower framerate that it was before.
You should also keep in mind the following limitations:
- Both NVIDIA SLI / AMD CrossFire can be used in desktop full-screen mode only (doesn't work in VR)
- Only full-screen mode is supported
- No performance boost on OpenGL API
- Some visual artefacts and texture flickering may appear
- When using AMD CrossFire, all the post-processing effects (including Auto exposure, SSR, SSAO, SSRTGI and so on) are rendered incorrectly
VR Applications#
LiquidVR and VR SLI technologies are not currently supported. Thus, CrossFire and SLI configurations provide no performance gain in VR applications.