Speed does not decrease with ECC memory -- you might be thinking of the extra cycle of latency associated with registered memory, and that's hardly a 100% penal

Speed does not decrease with ECC memory -- you might be thinking of the extra cycle of latency associated with registered memory, and that's hardly a 100% penalty. Unbuffered ECC DIMMs have no penalty compared to non-ECC DIMMs. Shipping 72 bits to the CPU instead of 64 bits costs a bit more power, nothing more. Your desktop CPU already has all the transistors needed to handle ECC memory, they're just disabled in consumer SKUs.