1.8 Unplayable Graphics: FPS freezes every few seconds (game continues)

RESOLVED by updating to Java 8u20

This error began with the pre-releases and is making 1.8 unplayable. I have not had this issue on any other version.

Every few steps (seconds) the game appears to freeze for a varying length of time, up to 1 second. After the freeze, the character and mobs are in slightly different places, so the game has continued on but it's just the visual that was frozen. This happens continually, even if walking in a small circle and not loading new chunks.

It's making the game unplayable in terms of combat and incredibly annoying otherwise. Building in creative mode is also impacted (for example) as you can end up breaking or placing unintended extra blocks during the lag/freeze.

I've tried changing all graphic settings down to the bare minimum and it still occurs (in 1.7.10 I play with all graphics settings maxed and have no issues whatsoever).