Is there any way to display memory speed in realtime like VRAM usage and temperature in MSI afterburner?
Yes and no. Yes you can display speed, but it won't achieve what you want. What I mean is: the card dynamically reclocks the GPU and memory in response to load, and GPU-Z (or other applications) can show that. However showing theoretical bandwidth throughput at any given point isn't possible without loading the memory subsystem (which would hurt gaming performance). Due to the interleaving you shouldn't have any significant performance hits under real-world conditions (it's a fast enough card to keep up with modern games), and any application that will demand 2GB+ of VRAM would likely bring the card to its knees regardless of memory bandwidth.
Tom's did a more in-depth test of the 192-bit bus here that you might also be interested in:
http://www.tomshardware.com/reviews/geforce-g … ng,3283-10.html