OK, back to the original issue - as a refresher, basically we've noticed that some lag is worse than other lag.
I've done some datalogging in three settings: CPU lag in the lag demo already provided, GPU lag in the same demo, and my game Airscape: The Fall of Gravity. At 30fps, here's what I noticed purely based on 'feel':
CPU lag: Felt perfectly fine, exactly what 30fps should be.
GPU lag: definite weirdness
Airscape: Absolutely horrible to control, nightmarish. Felt more like 5fps than 30fps.
Here are the dt logs I've made: [dt logged every tick]
CPU lag: very little deviation between dt
GPU lag: a fair bit of deviation between dt
Airscape: a LOT of deviation between dt
Ashley hopefully you can do something with this. There's definitely evidence here that something's wrong.
Everyone else, I've attached an updated lag test that you can use to test on your own machines. Bonus points for attaching to your games ( Aurel I'm looking at you )