I have asus HD-7770 with 2gb card and running it on win10. My system RAM is 16GB. I used radeon overlay performance monitoring and noticed after playing a game for 1 hour it shows around 5 GB RAM usage and 7 GB GPU VRAM usage. My card has only 2gb so how it is using 7GB ? Is it using system ram or page file. I do not notice any lag or fps drop.