What is ECC memory?
ECC SDRAM (error checking and correcting) modules have an extra chip that detects if the data was correctly read or written by the memory module. If the data wasn't properly written, the extra chip will correct it in many cases (depending on the type of error). Non-ECC (also called non-parity) modules do not have this error-detecting feature.
Who needs ECC memory?
The general rule of thumb in deciding what type of memory you need is to look at what's already installed in your system. If your machine does not support ECC, an ECC module will not operate in ECC mode, and it can affect system performance or may not work at all. If you're building a PC and deciding which type to use, the following guidelines should help. If you plan to use your system as a server or a similar mission critical type machine, it is to your advantage to use ECC. If you plan to use your PC for regular home, office, or gaming applications, you are better off with non-ECC. Current technology DRAM is very stable and memory errors are rare, so unless you have a need for ECC, you are better served with non-ECC SDRAM or DDR SDRAM.
Do I really need ECC SDRAM for my server?
When choosing your memory, you'll need to decide whether you want ECC or non-parity. ECC can find and correct some memory errors, but it comes with a performance price-- it will slow your system by about 2%. Fortunately, memory errors are rare in today's memory chips, so most average users don't have a need for ECC. If you're planning to use your system as a server or other "mission-critical" machine, we recommend ECC. If you're looking for maximum speed, we recommend non-parity.