ECC question ??

When adding new memory, you need to match what is already in your system. You cannot mix ECC with non-ECC (non-parity) memory.

You can determine if your system has ECC by simply counting the number of black memory chips on each module. ECC (and parity) memory modules have a chip count divisible by three or five. This extra chip 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. Any chip count not divisible by three or five indicates a non-parity memory module.

Using ECC decreases your computer's performance by about 2 percent. 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-parity (non-ECC) memory.

ECC RAM has a hardware error-correction protocol built into it. Basically, there's code built into the memory chips that can detect memory errors. As this requires additional or at least more complicated hardware, ECC RAM tends to be slightly more expensive than an equivalent non-ECC chip.

Pretty much all denominations of RAM are available in both ECC and non-ECC versions, and motherboards don't really care which you use, though you should only use one kind in any given computer.

The vast majority of RAM currently in use is non-ECC. Pretty much only highly sensitive, mission-critical applications require ECC-type RAM, as personal and most commercial computing gets along just fine without it, and the error-correction algorithms tend to cause a performance hit.

ECC - short for Error-Correcting Code memory, a type of memory that includes special circuitry for testing the accuracy of data as it passes in and out of memory.

It depends on the mainboard if it supports ECC memory (the most for home PCs don't). ECC memory is mostly used in servers running 24/7/365.