The game will run for a time on less than 512MB of VRAM. There is a memory leak in the OpenGL driver, so the less ram, the quicker to crash. The new textures require a significant amount of VRAM. For integrated graphics cards, avoid installing the field and battle textures. Intel HD GPU's struggle to run a fully modified FF7. These cards have varying amounts of VRAM available depending on the system. Results will vary.