These logs are for 3 single player games. The first was created in 1.8 previously, and then run with the developer log. It ran smoothly. The second was previously created in version 1.7.x and run in 1.8, and it was very choppy overall. The third was created and run in 1.8 with the develop logs up; it ran very smoothly.
This time around, there was no trouble in creating the game in version 1.8. But that first time, there were problems.
You don't have to run or jump for this to happen. You just need to turn. Sometimes it happens without the player moving at all.
This seems to be happening in game worlds that were created in version 1.7.10. These game worlds are extremely poor when it comes to how smooth they run. This applies to the same game worlds when played in version 1.8. There should be a tool to update these worlds to work properly with version 1.8.