GPU stuff - lower performance than logical?

[Colin S]

Here is a shot I took with GPU-Z running in the foreground. I forgot to enable framerate display in X-Plane, but rest assured it's sitting somewhere around 5-10 frames per second. Please note that I currently have three monitors connected and have X-Plane rendering at 4480x1080, so I'm not too upset by this. Well, I wouldn't be too upset if I didn't see what I see in GPU-Z. I don't understand graphics cards too well, so as reddit would put it, "explain like I'm five..." if you even can explain. Why is it that I am "enjoying" a clunky, jumpy experience in a graphics intensive program when it claims the GPU load isn't even at 50%? How do GPUs determine when to slack off and do diddly squat? The monitors, adapters and cables cost me a combined $25.68 so I won't be too sad if my GTX780 can't handle them... but even at low settings? As you can tell from the screenshot, my settings are pretty low right now. And frame rates don't change whatsoever whether I crank everything to maximum or drop everything to FS95 quality.

PS - just loaded the default 747, which is a bit hard on the GPU due to poor modeling. It only chopped about three frames per second off the original 5-10. This is confusing me a lot. Anyone who can briefly explain the logic of how GPUs work will be much appreciated

PPS - Just shrunk the window down to nothing, the smallest X-Plane can render. Still at 6fps. Even with the default 172. What is going on.

Edited September 27, 2016 by Colin S

[sundog]

I think that's a 3GB video card, which means you're running pretty close to being out of VRAM there. Once memory starts swapping, performance is done.

Your large display resolution is eating some of that, but as for what's consuming the rest - that depends on the add-ons you have installed. Basically you installed something that tipped your VRAM usage over the edge, I think.