Mon Oct 13, 2014 3:38 am by bob
Process Explorer has a few graphs. You simply want the ones right at the top (double click on them or goto View - System Information). This will give you the overall GPU information, which is what you need as you need to know the total of GPU and GPU Dedicated memory that is in use (oh and the GPU system memory too, which may be interesting).
As was suggested earlier, you may want to check out the CPU strategy wizard and not use a dedicated core per instance. You have 4 cores, 18 games, so 2 cores have 5 games, 2 cores have 4 games, and this is not including all the other things running too. As some games will not require the same resources at the same time, you could easily be starving the ones that do - the All Windows/All Cores strategy as Lax suggested would help with this. Also, you have foreground/background FPS settings of 60/30, which is damn hopeful IMO with the number of clients and the hardware you've got. I'd try setting it to 30/20 or 30/15, and then slowly move up the background setting up to 30 if it doesn't choke. This of course will be applicable if your GPU is not showing signs of memory pressure.