The Quadro NVS 450 is a really slow chip… you can’t expect great performance. When you say “slow”, you do mean that do don’t even have 60Hz with only a glClear?
Your framebuffer worth 100 MB… 6GB/s @ 60Hz (hopefully dispatch across all cards but I believe copied on all cards) for a maximum of 11GB/s… It might be tricky quite quickly.
Yep, I did not expect stellar performance, but even with only a glClear, it can’t sustain 60Hz, or even 30Hz… I did not bother to measure the actual framerate as the refresh is really perceived as slow…
12 screens should be a nice playground, just have to figure out how to animate something on them…