Confusion over memory usage

  • OK, I set up a large scene, couldn't use GPU to render, so started trimming the un-needed bits. Got it down to a point where the GPU could cope, so all good so far. I decided to investigate changing the image used in a material, so took the wood floor .jpeg which was 1600x1600 and reduced it to an 800 x 800 image with medium compression. It went from a 1.2Mb file to something like 170k. When I use that in the actual scene, the memory usage went UP, not down (by about 2Mb). I can only assume that's because it's tiled across a large surface and that Poser calls on the image multiple times to cover that surface? Seems a bit crazy (and counter intuitive) to me... but is that really how it works?