How to enable SLI in OpenGL?

Question

I am running openGL 4.6 with glad and GLFW with the latest nvidia driver. Sli is enabled in nvidia control panel and I'm running on a x299 platform with dual 1080ti's in SLI.

Currently only GPU1 is running at 100%, while GPU2 is at 0%. I have tried to overload the vertex shader and fragment shader with a loop just to test if SLI is working properly, but GPU2 is still at 0%.

I have tried to force AFR in nvidia control panel which utilize both GPU's at 100%, but no fps increase.

It sounds like you have not selected the correct device in your GL code. If your mboard/gpus are sli compatible, then when you query available devices, an SLI device should be there. — Ian Young, Feb 13 '19 at 09:23
https://stackoverflow.com/questions/43811699/opengl-multi-gpu-support — Ian Young, Feb 14 '19 at 10:12

score 0 · Accepted Answer · answered Feb 16 '19 at 21:11

I solved the problem, I just forced AFR1 trought nvidia control panel, then in my code I chose to use my main monitor in full screen when I created the window. I have two monitors, so when I chose monitor[1] I had no scaling, but with monitor[0] got me almost 100% sli scaling. i.e

GLFWmonitor **monitors = glfwGetMonitors(&count);

window = glfwCreateWindow(screenWidth, screenHeight, "OpenGLTest", monitors[0], NULL);// monitors[0] gave full scaling monitors[1] gave no scaling, also force AFR via nvidia control panel under "sli rendering mode".

How to enable SLI in OpenGL?

1 Answers1