If you use /setblock to place 2 end gateways on top of each other in the overworld and stand in it, it causes a huge FPS drop.
Not standing in the Gateway: 60-80 fps
Standing in Gateway: 1-6 fps
Environment
Windows 10 Pro Insider Preview Build 10547, Minecraft 15w39b, Java 8 u25
Surface Pro 3 Core i3 model
Please force a crash by pressing F3 + C for 10 seconds while in-game and attach the crash report (
[minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/finding-minecraft-data-folder]) to this ticket.Please attach the complete output of the "Game Output (Your Minecraft name) " which can be found on the fourth tab of the launcher to this ticket.
If the launcher closes after game start, please edit your profile and select "Launcher visibility" then, "Keep the launcher open".