Are you saying you have monitors plugged into both the onboard graphics and the 290X? If so, you definitely aren't using Dual Graphics, as that (like Crossfire) requires all displays to be on the primary GPU, which in your case is the onboard GPU.
I don't think you'd get any benefit from Dual Graphics, so I'd recommend plugging your primary (gaming) monitor into the 290X, and the other monitor into the onboard. That should make fullscreen games run on the 290X, while letting you use the lower-power onboard graphics to drive the second monitor (will keep the 290X clock speed down in idle).
As for that performance monitor, I'm not sure what to make of it. It's very unstable, and crashes after a short while when I run it. Before doing so, it reports the VRAM usage just as Afterburner does, which is twice as large as it actually is (because of CF). In my case at 2560x1600 with AA, it got up to 3240MB VRAM usage before the monitor crashed again. Again, that really means 1620MB usage.
Your screenshots show usage above 2GB, which might mean several things. It might mean you do have Dual Graphics enabled, and that the number reported is out of 4GB (2GB onboard, 2GB for restricted 290X). It might mean only the reported VRAM capacity is incorrect, and you're actually using >2GB on the 290X (which means you have a ton of texture mods, very high AA, very high resolution, or some combination of them all).
What does MSI Afterburner report?