After new update demo seems better, though I don't understand the VRAM usage of the game

After the September 28th Update, the texture loading problem seems better, tho it still persists at some points. But there is one more thing I still cannot understand. In benchmark mode the game displays 3,34GB VRAM, tho I have 4GB of it. MSI Afterburner displayed 3245MB usage of VRAM, the game displayed 3,00. Please investigate this why the game managing VRAM differently, than other games. As I checked it should 3,92GB available VRAM, since the remaining is used for other hardwares, which is 72MB.