Wow, anonymous, it's too bad all of those supercomputing guys didn't ask you! You could have set them straight before they wasted all that time and money. I guess you'd better let the folks at top500.com know, quick - they must have missed it before now.
OR, just MAYBE, you have no idea what you're talking about. It's a relatively simple exercise in software development to identify spurious results via multipl iterations. ECC memory won't protect you from processor faults and other glitches anyway, so the software has to be robust enough to allow for bad results even with expensive memory.
But thanks for playing.