[Beowulf] X5500

[Greg Lindahl]

On Thu, Apr 02, 2009 at 09:05:26PM -0700, Ellis Wilson wrote:

> Though entertainingly put, it would be an error to say "ECC is a 
> requirement" for everyone in a "cluster group".  I can think of more 
> than just a few purposes for clusters that truly do not require the 
> accuracy guaranteed by ECC RAM.

The only big cluster I can think of built without ECC was built by a
guy whose research area was making computations reliable by doing
additional inexpensive computations to check the answer. While that
was really clever, the cluster was intended to be a general purpose
machine, and this answer-checking thing can only be efficiently done
for a subset of algorithms. Oddly enough, the cluster was subsequently
upgraded to ECC.

I have never run into a situation where a cluster would be improved by
leaving ECC off. I buy ECC for desktops, too, it's a small price to
pay to avoid engineer downtime.

-- greg