I can confirm that the value in memorysize in enblocal.ini is important. Sometimes you need to try and tweak the value much lower than theoretical values: I have a 3GB VRAM graphic card (970 GTX) + 16 GB ram, OS takes 4GB. I should be able to go up to 14GB in memorysize. But after trial and error, my good value for crisp textures is 8000 (even at 10000 I see blurry textures).