[jltsiren]

It's usually bottlenecked by memory latency, not bandwidth. People talk about bandwidth, because it's a simple number that keeps growing over time. Latency stays at ~100 ns, because DRAM is not getting any faster. Bandwidth can become a real constraint if your single-threaded code is processing more than a couple of gigabytes per second. But it usually takes a lot of micro-optimization to do anything meaningful at such speeds.