[osg-users] CPU load and performance drop when running 2 instances of OSG app on 2 GPUs

[Roy Lichtenheldt]

Hi,

I wrote a simulation app using OpenGL compute shaders based on OSG (so one frame equals one simulation step). To run several simulations at one time on one pc, I use several X-Screens to address the different cards. For maximum performance Vsync is disabled.

This works fine so far, but if I run a simulation (osg app) on both of the cards, i.e. each on one of the x-Screens (doesn't matter if rendering to a frame buffer or to the screen), the fps drop by 50% and the CPU as well as GPU load of the applications drop from ~100% to 50% too.

Nvidia optimizations for multithreading do not make any difference.

I use mainly Nvidia gpus (Pascal) and Linux with Xserver.

How can I achieve 100% load on both gpus and cpus running the two apps?

cheers,
Roy

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