[wtallis]

What's the performance overhead of ECC come from? I know registered memory has a small but measurable latency penalty, and ECC modules are often also registered, but a simple parity check in the memory controller should be a pretty fast circuit.

[gspetr]

These days ECC testing is supposed to be integrated into the CPUs.

Enthusiast testing seems to support this with overhead being <0.5% even for Reg ECC:

https://www.pugetsystems.com/labs/articles/ECC-and-REG-ECC-M...