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Reinforcement Learning · AMS 691

Comparing GRPO and PPO on Traditional Reinforcement Learning Tasks

A comparison of PPO and GRPO in Atari Galaxian, examining training stability and performance when learning from visual observations.

ATARI GALAXIANOBSERVATIONPPOGRPOACTION / REWARD

Overview

The group project compares Proximal Policy Optimization (PPO) and Group Relative Policy Optimization (GRPO) in the Atari Galaxian environment. It examines the behavior of value-based and group-relative advantage estimates in this visual control task.

Topics & methods

  • Train PPO and GRPO with 16 parallel actors over 150 iterations.
  • Use a learning rate of 0.0001 and discount factor of 0.99.
  • Compare training returns, learning stability, and example gameplay.

Discussion

PPO trained more steadily and achieved higher training returns than GRPO in this configuration.

Read project report