Non-ECC Unbuffered and unbuffered

[sunderland]

whats the difference between the 2,as was looking at corsair it has
4GB (2x2GB) CorsairTwinX DDR3 PC3-10666 (1333) 240 Pin, Non-ECC Unbuffered, CAS 9-9-9-24, 1.50V
and
4GB (2x2GB) CorsairTwinX XMS3, DDR3 PC3-10666 (1333MHz), 240 Pin, Unbuffered, CAS 9-9-9-24, DHX

one has non ECC unbuffered and the other has unbuffered,

 

[FoxEye]

One may have ECC, the other certainly doesn't?

Buffered memory (aka registered memory - registers are buffers of sorts), will not fit in a memory slot designed for unbuffered RAM, AFAIK.

Unbuffered RAM (the kind we all use) is either ECC or non-ECC. ECC = error correction. Reduces errors, but doesn't 100% eliminate all errors.

With RAM tho, we're talking 1 error per few thousand hours use, or something. ECC isn't all that useful for a home gaming rig.