Non-ECC memory is computer memory that lacks error checking and correction functions. Non-ECC memory is the most common type of memory in consumer-grade computers; ECC memory is found in servers and scientific computing.
Memory correction is not needed except in the most sensitive scientific and financial applications. Even slight amounts of data corruption are unacceptable in these usage cases, so memory with error correction capabilities is used. Most commercially available motherboards designed for home and small business use do not function with ECC memory.
The average incidence of memory error is once per gigabyte of memory per month of uninterrupted operation, as of 2014. Because very few home and small business machines have significant uninterrupted uptime, there is little risk of a memory error. In the rare case that a memory error does occur, a system restart corrects the issue. Because home systems do not require constant uptime, restarting the machine is an acceptable solution. Financial and scientific applications have greater need for uninterrupted uptime, and use ECC memory to prevent memory errors as a result.
Memory errors are caused by natural background radiation, which comes from both radioactive isotopes found on earth and cosmic rays originating in supernovas. The occurrence of memory errors is much higher for computers aboard spacecraft, particularly during solar flares and other events that increase the incidence of background radiation.