Persistent textures

Im not sure if Blender already keep loaded textures in memory, when rendering an animation, but if it doesnt, this idea is a must. If textures are gigabytes, keeping them in memory will save time several seconds per each frame. And if rendering itself takes only 15-20 secs, relative time save is significant. And over time, even more so. For instance, if textures takes 5 gigabytes and reading speed of hard-drive is 500 Mb/s, it takes 10 secs to load the textures. And if animation is 500 frames long, time save is about 80 minutes.