Textures resolution

Hello, I have such a problem. I have World War 3 game. When I set the texture options on the medium they look terrible like very low, and when I set to high they load nice but the game is terrible lags. When I added r.Streaming.UseFixedPoolSize = 1 to the engine.ini file and set in game texture option i to high, the textures loaded nicely and the game did not lags, but when I want to start the game on a new map I have to turn the game off and restart, the textures to load. Can I bypassing it somehow? IP Have only 2gb vram graphic card