Will ecc memory work on a non ecc motherboard?
ECC Memory has an extra chip on the memory that performs Error Checking and Correcting functions. It's really only recommended for machines being used as servers.
For home systems, non-ECC memory is recommended unless you KNOW you need the ECC function. This is because ECC and non-ECC memory can almost always be mixed in the same system with no problems. If you mix these types of memory, the system will run as if all the memory was non-ECC.
Non-ECC memory is also recommended because it runs a little faster than ECC memory since it doesn't need to do the extra error checking. ECC memory is only really beneficial if you're going to be processing massive amounts of data (like a server does) and all data needs to be 100% accurate. Non-ECC is all that's needed for 99% of the computers out there.
What is registered memory?
A memory module that contains registers that hold the data for one clock cycle before it is moved on to the motherboard. This process increases the reliability of high-speed data access. Registered memory modules are typically used only in servers and other mission-critical systems where it is extremely important that the data is properly handled.