ECC memory on PCs

Error-correcting code memory (ECC memory) is a type of computer data storage that can detect and correct n-bit data corruption which occurs in memory. ECC memory is used in most computers where data corruption cannot be tolerated under any circumstances, like industrial control applications, critical databases, and infrastructural memory caches.

ECC protects against undetected memory data corruption. Typically, ECC memory maintains a memory system immune to single-bit errors: the data that is read from each word is always the same as the data that had been written to it, even if one of the bits actually stored has been flipped to the wrong state.

Linux kernel creator Linus Torvalds went on a frustrated rant about the lack of Error Correcting Checksum (ECC) RAM in consumer PCs and laptops.

… the misguided and arse-backwards policy of “consumers don’t need ECC”, [made] the market for ECC memory go away.

The arguments against ECC were always complete and utter garbage. Now even the memory manufacturers are starting to do ECC internally

Intel has traditionally thought that ECC is something only for expensive servers. AMD has made ECC available also on for normal PCs: All Ryzen CPUs will work with ECC memory if motherboard supports it.

Bit errors introduce instability into systems and corruption into data. Although ECC RAM can’t mitigate RAMBleed-style attacks that deduce the values of adjacent memory, it can generally stop Rowhammer attacks.