The problem with the memory on the laptop HP

Ganyayut on the old HP Pavilion g6 2281sr.
Graphics it consists of Intel HD Graphics 4000 + AMD Radeon HD 7670M.
Installed 6 GB RAM
What is salt when enabled only the integrated GPU of 1GB VRAM that are available and used 128 MB. It is necessary to include discrete video memory up to 4GB and 1GB is used. Screenshot attached



And when playing some sort of game over time integrated card eats the whole RAM and game to feed there is nothing, then popping up an alert that the system has no memory and climbed logs. Before reinstalling Windows had no such problems (Windows 8.1 64-bit)
How to fix this problem, upgrade is not an option