When I have a hig resolution texture pack, minecraft takes too much memory. I set a limit to My Optifine Minecraft instalation. I cheked the JVM Arguments, and minecraft keeps taking more memory that the limit or run out of memory. It happends too with my Modded Minecraft version. I have to remove the memory limit. And with a clean instalation too. With the default texture pack happends too. I cant play minecraft without setting a memory limit. And i can't increase the RAM memory, because I dont like to open my computer.