How Learning Rate Scheduling Works
Constant LR Problems
Why a fixed learning rate fails
High learning rate: loss oscillates as the model overshoots the minimum repeatedly.
Step 1 of 6: Constant LR Problems
Why a fixed learning rate fails
High learning rate: loss oscillates as the model overshoots the minimum repeatedly.
Step 2 of 6: Step Decay
Reduce LR at fixed intervals
Moderate step decay gives a nice staircase pattern. Each plateau lets the model settle before reducing the step size.
Step 3 of 6: Exponential Decay
Smooth continuous decrease
Moderate decay rate produces a smooth curve that gradually reduces exploration over training.
Step 4 of 6: Cosine Annealing
Wave-like schedule with warm restarts
Moderate cycle length creates a smooth annealing curve. The cosine shape spends more time at low LRs for fine-tuning.
Step 5 of 6: Warmup
Start slow, ramp up, then decay
Moderate warmup lets the model build reliable gradient statistics before applying the full learning rate. Standard for transformers.
Step 6 of 6: Cyclical LR
Periodic exploration and convergence
Moderate cycles balance exploration and convergence. The triangular wave provides natural warmup and cooldown within each cycle.