In article <1154935321.957349.207640@h48g2000cwc.googlegroups .com>,
"paulmd@efn.org" <paulmd@efn.org> wrote:
> bob@coolgroups.com wrote:
> > Anyone know if this is ECC or non-ECC?
> >
> > http://www.compusa.com/products/prod..._Memory_Module
> >
> > No one at CompUSA knew.
>
> ECC Ram is usually supereasy to spot, because, it either says ECC on
> the label. Or it has a funky arrangment of chips (not always).
>
> If it doesn't say ECC it's probably not. ECC costs more, which is
> another hint. Same applies to things like registered or buffered, or
> oddball ram.
>
> PS: I suggest buying from a store that knows what exactly they're
> selling.
An example would be finding a DIMM with eight chips on either
side. That would be non-ECC. If the DIMM has nine chips on
either side, that would be ECC. (And not just any chips you
find, I'm talking about the ones that are identical to one
another.)
The ECC DIMM has a 72 bit wide interface, which is 9 chips of 8 bits
each. The non-ECC DIMM has a 64 bit wide interface, like
8 chips of 8 bits each.
(And there are too many different DIMM formulations, for me to
list all the combinations of ECC versus non-ECC. Yes, I'm
that lazy...)
BTW - I could not view the URL above, because it says
"Compusa is closed". Meaning they are working on their
server, I guess.
Here is a picture of a nine chip ECC PC133 DIMM.
http://www.upgradecomputermemory.com...AM-Memory.html
This one is non-ECC and the ninth chip is missing.
http://www.upgradecomputermemory.com...AM-Memory.html
HTH,
Paul