This has been very annoying to me and my sister ever since 1.8 came out, this is a MAJOR problem probably causing the lag a lot of people have been talking about. I hope you can fix this before 1.8.2 comes out. Anyway, here is the problem: My computer used to get about 4-6 render distance while still staying fluent (about 45 fps ) with 1.7 if i turned the render distance up to 16 it would generate chunks slower and decrease fps to about 15, But now with the long awaited 1.8, My fps has decreased to about 25 on 4 render distance if i go above about 8-6 render distance fps drops to 10-5 and flickers says (not responding) at the top of the window, but most importantly something else very weird happens, about 20 blocks to the side of me, these random warped copy and pasted chunks with no physics start appearing and violently flickering into other chunks similar to them (seen in the photos below) this happens to me on any world in any biome singleplayer or multiplayer. My sister (who plays Minecraft with a better graphics card) now is experiencing the same problems. Please fix this or at least reply if possible!