On the ESX Host Details screen of a VMWare host what's the difference between the Memory Used gauge and the Virtual Machine Memory Consumption line graph? I would assume (which is always a mistake) that the total VM memory consumed would be a break down of the memory used or at least close. However my readings aren't even close, 80% memory used, 55% memory consumed. I don't believe ESX would use 25% of the memory for it's OS. What I am missing?
It likely has more to do with time. So "point-in-time" vs. average over the time interval. Check the sample intervals on the respective resources.