Latency is the cost of performing a transaction, not useful to the transaction itself. This can be, for example, code generation costs and memory management costs in the VM, required for a transaction in a Java application to complete. Unpredictable latencies cause trouble, since it is hard to determine load levels over time. Sometimes, it is better to pay for predictable latencies with lower total throughput.

See also Stopping the world, Deterministic garbage collection, Concurrent garbage collection, and Parallel garbage collection.