Elastic Cloud Compute (EC2)
Instance Types
T type instances are general purpose with a baseline CPU performance and burstable to higher limits. The Unlimited option allows bursting to above baseline performance for an unlimited amount of time. CPU credits are still accumulated for time spend below the baseline performance. You can choose between Unlimited to ensure the CPU will never be throttled or Standard to ensure you're billing is predictable, at the expense of being throttled when CPU credits expire.