ECC memory

[Eric Hoyt]

Hi everyone,

I posted a message a few weeks back as to my dilemma of choosing between
Intel and AMD chips.  A belated thanks to all those who replied.

After deciding to go with Athlons and the ABIT KT7A motherboard, I came
across a new problem.  We'd like to use ECC memory, but VIA 133/133A based
motherboards don't seem to have ECC support.  I've seen all sorts of
conflicting accounts, but it seems to be the case that there is no ECC
support with these boards.  The odd thing is, I've seen several companies
selling their commercial Beowulf systems with KT7(A) mobos and ECC
memory.  Since non-ECC motherboards can sometimes use ECC memory with the
ECC functionality disabled, are these companies just fooling people by
selling ECC memory along with boards that can't use ECC?  

For me, this also brings up the question of how ECC works.  Does the DRAM
module perform the error correction, or does the chipset perform error
correction?  From some research and common sense, it seems the chipset
does it - otherwise, what's the point of bringing the extra 8 ECC lines
off of the memory chip?

Finally, have people found ECC to even be necessary?  From some of the
stats we've seen, it seems like ECC is the way to go.  But it also seems
like there are a lot of systems out there running reliably without
ECC memory.  Any experiences people have had with and without ECC would be
helpful.

Thanks again for any help and ideas.

Eric Hoyt