ECC and non-ECC at same speed perform identically in single-thread tasks.

Nope. Not in a way you’d ever notice.

ECC memory does have slightly higher latency because it checks and corrects errors on the fly. But we’re talking about single-digit nanoseconds. For a single-thread workload — say, gaming or a script that runs on one core — the difference is so small it won’t show up in benchmarks unless you’re measuring down to the noise floor.

If you’re building a workstation and need the reliability of ECC (e.g., for scientific computing or a file server that runs for years), don’t worry about losing single-thread performance. It’s not there.

The bigger thing to watch is that ECC often runs at slightly lower clock speeds or higher CAS latency in practice because of how motherboards configure it. If you compare two identical sticks at the same speed and timings, they perform the same.

Future You won’t curse your past self for choosing ECC.