Loading a www texture makes my game freeze for a second

I'm trying to load a texture via WWW dynamically. I am setting the url variable and then calling the following Coroutine. The code works, but when the texture is set to the www result then the game freezes for about a second (I'm assuming while the texture is applied). Is there a way I can prevent this from happening.. perhaps by loading the texture into memory first or something?

Of note: the texture is 4096 x 2048 and is about 715k in size. I've tried doing the same with a texture 1/4 the size and it still freezes, just for a shorter period of time.

 IEnumerator LoadMapLarge() {
     WWW www = new WWW(url);
     yield return www;
     renderer.material.mainTexture = www.texture;
 }