[Beowulf] ECC Scrub, which setting?

David Mathog mathog at caltech.edu
Mon May 19 09:09:34 PDT 2008

I finally managed to get into the BIOS in the broken IBM x3455 (the
problem turned out to be a bad stick of Crucial memory in the first
memory slot), and once there, discovered that not only was ECC enabled,
but that this machine has a plethora of ECC settings.  These were
"Disabled, Basic, Good, Super, Max, User".  It is currently set to
Basic, which scrubs every 5.24 ms.  The higher settings scan more
frequently.  This level of ECC configuration is new to me, on previous
systems it was just scrub or no scrub.  Is "Basic" "good enough" or
should I use a higher setting?  There are currently 12Gb of RAM, it will
be back to 20Gb when the bad memory is replaced.  The machine only does
research calculations, so a missed bad bit will it worst give a wrong
result - no need to worry about melted reactor cores or anything like
that.  An OS crash would be inconvenient but not a serious problem.


David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech

More information about the Beowulf mailing list